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SantaMonica
10-01-2011, 05:31 PM
Subscribe to this sizing guideline (http://algaescrubber.net/forums/subscription.php?do=addsubscription&t=1419)


What size scrubber do you need?
(edited November 2022)



Any scrubbing is good scrubbing. Even a small algae scrubber on a big tank will help your glass stay clearer longer. Beyond that, the basic guidelines for algae scrubbers are based on how much food you feed each day. These guidelines are to help you get the minimum size (or number) of scrubbers that will still do a good job of total filtration. You cannot "over scrub", so having a larger scrubber (or more of them) simply works more like the oceans and lakes do, which have enormous amounts of algae to do all the filtering. And the scrubber can go anywhere in your system; it will filter the same.

So, scrubbers are sized according to feeding. Nutrients "in" (feeding) must equal nutrients "out" (scrubber growth), no matter how many gallons or liters you have. So...

An example VERTICAL upflow or waterfall screen size is 3 X 4 inches = 12 square inches of screen (7.5 X 10 cm = 75 sq cm) with a total of 6 watts of red LED light for 18 hours a day. If all 6 watts of LED light are on one side, it is a 1-sided screen. If the watts are divided on each side of the screen, it is a 2-sided screen. This should be able to handle the following amounts of daily feeding:

1 frozen cube per day (2-sided screen), or
1/2 frozen cube per day (1-sided screen), or
10 pinches of flake food per day (2-sided screen), or
5 pinches of flake food per day (1-sided screen), or
10 square inches (60 sq cm) of nori per day (2-sided screen), or
5 square inches (30 sq cm) of nori per day (1-sided screen), or
0.1 dry ounce (2.8 grams) of pellet food per day (2-sided screen), or
0.05 dry ounce (1.4 grams) of pellet food per day (1-sided screen)

Problem rocks: Each 50 pounds (2.2 kg) of nuisance algae covered live rock you have adds 1 cube a day. This rock is usually older than 3 years, or it's from another tank.

Water flow or air bubbles is always 24 hours; water flow is at least 35 gph per inch of width of screen [60 lph per cm], EVEN IF one sided or horizontal.

Floating surface scrubbers with strings: Screen size is the size of the box (Length X Width), and is 2-sided because the strings grow in 3D.

Clean algae:

Every 7 to 10 days, or
When it's black, or
When it fills up, or
When algae lets go, or
When nutrients start to rise

However these are just starting points; a lot of your tank filtering (especially in saltwater) is based on your live rock, so their condition plays a part too in what size scrubber to make, as well as what type of feeding you are doing, and what other filters you will be using. Here are some specific guidelines:

FRESHWATER:

Since freshwater grows extremely thin, long algae, scrubbers without strings are recommended. This is because you will probably need to clean the scrubber in your sink with a toothbrush (instead of in-place harvesting while still in your aquarium), and it's easier to brush a flat wall than it is to brush strings. So flat-wall scrubbers such as wide-panel bubble upflows work well in freshwater. Also, since the thin stringy freshwater algae will flow out of holes in the scrubber, if you put the scrubber in your display (where the animals are), the animals will learn to eat out of the scrubber and you will therefore be able to feed less. If you intend to do a large part of your feeding this way, multiple scrubbers will allow the feeding (and filtering) to continue in one scrubber when you have cleaned the other. Waterfall types are not recommended for freshwater because the long thin growth flows down the drain.

SALTWATER:

With saltwater, you can get thick dense growth in the scrubber, which is when strings are an advantage (to hold on to the growth in the middle of big open compartments). So adding strings to a scrubber is acceptable, and the decision is based on size and on where you want to put it, and also on how you want to clean it. Saltwater tanks which use live rock (even if the rock is "dead") will need to take into consideration the history of the rock: If it came from a tank with algae problems, each 50 pounds (23 kg) of this rock will add 1 cube a day to your feeding. This is because the rock is really just coral skeletons which absorbed nutrients (mostly phosphate) from the water when the nutrients in the previous (or current) tank were high, and these nutrients will then start coming out and flowing into the water when your scrubber starts working.

After looking at size, the main consideration is where to put it. Since scrubbers filter the same in any location, it is just a matter of placement. Unlike freshwater, the thicker growth in saltwater usually does not flow out of the holes or drains, so you can't rely on it for automatic feeding (although you can manually take some growth out). And similar to freshwater, multiple smaller units are better than a single larger unit.

REEF:

Reefs are the same considerations as saltwater, with the exception that some people like the reef to run as natural as possible, meaning it's filtered by algae alone. With that in mind, here are some more details and options:

1) If you are building a reef tank which is new, and the rocks are coming from the ocean or from a low-nutrient tank with no algae problems, and if you will just be feeding the fish sparingly, and if you DO want to have other filters and water changes, then you can just use the cube-feeding recommended sizes of the scrubbers.

2) If you are building a reef tank which is new as in #1 above, but you DON'T want any other filters or water changes, then double the recommended scrubbing amount in #1. This will supply the corals and small fish with the most amounts of food particles, and will allow filtering and feeding to continue in one scrubber after you cleaned the other.

3) If you are building a reef tank which is new as in #1 or #2 above, but the rocks are coming from a nutrient-problem tank which had measurable phosphate or hair algae problems, then the rocks will be soaked with phosphate and this will supply more phosphate to your new tank than your feeding will. So use the guideline of 50 pounds of rock = 1 cube of feeding, to add to the recommend scrubbing size.

4) If you are adding a scrubber to an existing reef tank, and the tank has no measurable phosphate and no nuisance algae, and if you have other filters and water changes and you DO want to keep them, then you can just use the cube-feeding sizes of the scrubbers.

5) If you are adding a scrubber to an existing reef tank as in #4 above but you DON'T want to continue using the other filters or water changes, then double the scrubber amount recommend in #4, preferably by having multiple scrubbers which are cleaned alternately. This will keep one scrubber filtering and feeding when you have cleaned the other.

6) If you are adding a scrubber to an existing reef tank that has measurable phosphate and green hair nuisance algae on the rocks, and you DO want to continue using other filters and water changes, then you can just use the recommended cube-feeding sizes. Use extra light (more LEDs) if possible because the higher phosphate in the water needs brighter LED's to make the scrubber grow green sooner. And if you double the amount of scrubbing (two units instead of one), the problems will clear up twice as fast because there will be twice the amount of algae absorbing the nutrients out of the water, especially when you clean one of them.

7) If you are adding a scrubber to an existing reef tank that has measurable phosphate and green hair nuisance algae on the rocks as in #6 above, and you DON'T want to continue using other filters and water changes, then double the amount of scrubbing recommended in #6.

8) If you are adding a scrubber to an existing reef tank that has NO measurable phosphate, but has LOTS of green hair nuisance algae on the rocks, then you need the strongest LEDs possible because the rocks are already full of phosphate, and the algae on the rocks is absorbing this phosphate, meaning you need the strongest scrubbing possible in order to out-compete the algae on the rocks. This is the hardest situation to fix, so you should use as much scrubbing as possible with the strongest LEDs available, and use as many other filters and water changes as possible too, until the algae on the rocks turns yellow and lets go. Be careful however, to start your scrubber with very reduced light, because very strong light will stop algae from being able to begin growing.

End

NOTE: The following posts, below, were from 2011 (the old guidelines), and are not about the current guideline above.

NOTE2: This calculator might help, if it is still working:
https://docs.zoho.com/sheet/published.do?rid=b0tmj6d91ce368ee542aba6b2b670ae00 412b

jnad
10-11-2011, 02:58 PM
Thanks, this is great info.

Have just a little question when it comes to size / design of the screen:

For example, have a screen that measures 10 cm x 20 cm the same filtering capability as a screen measuring 20cm x 10 cm?

jnad

SantaMonica
10-11-2011, 08:30 PM
Should be the same.

bguile
10-15-2011, 07:14 AM
So is there no more need to double the screen size if it's only lit from one side??

dtyharry
10-15-2011, 09:22 AM
Can only feed half as much for the same screen size if lit from one side.

SantaMonica
10-15-2011, 09:34 AM
If all the watts are on one side, you can feed half as much, because the roots die faster.

sharkman121
10-19-2011, 07:24 AM
i dont feed cubes. Usually a couple pinches of New Life Spectrum per day. Have a 130 gal FOWLR.

was considering going with a 15 x 15 double screen with a 75watt bulb on either side. wat you think?

SantaMonica
10-19-2011, 01:25 PM
No double screens.

You probably mean a 13 watt bulb, which is way way too small for a 15" screen.

See the feeding guideline at the top.

tebo
10-19-2011, 01:49 PM
Based on this guide, if I have a net of 90x20 cm = 1800 sq cm, that means I can handle 20x of food

Is that correct?

SantaMonica
10-19-2011, 02:08 PM
Yes, if you have 20x the watts.

kerry
10-19-2011, 02:48 PM
i dont feed cubes. Usually a couple pinches of New Life Spectrum per day. Have a 130 gal FOWLR.

was considering going with a 15 x 15 double screen with a 75watt bulb on either side. wat you think?
I think he means double sided.

tebo
10-19-2011, 05:59 PM
thanks :D

leebee
10-21-2011, 07:32 PM
Wow, those new screen sizes are so much smaller than before. Might get a scrubber in my sump now. :o

SantaMonica
10-22-2011, 11:25 AM
Keep in mind you should size to fit what you will be feeding in the future, not what you are feeding now.

leebee
10-22-2011, 02:14 PM
Only feed 1 cube per day, can't see that changing, so I've gone from a full sheet of plastic mesh to one about the size of my palm. That's amazing.

new2scrub
10-25-2011, 07:04 AM
my screen is 10" tall and 16" long with 4 26 watt bulbs(2 each side). right now I feed about 3 total cubes per day. Am I good?
that's 160 total square inches rite?
52 watts per side rite?
104 total watts rite?
1.5 watts per inch rite?

SantaMonica
10-25-2011, 10:06 AM
You have more area than you need. Try to have at least one watt per square inch. You could remove half your screen, and put all the watts on the remaining half.

new2scrub
10-25-2011, 10:11 AM
i think I have 1.5 watts per inch,how many watts am I shooting for per inch? I can cut the screen so It is shorter (top to bottom) will that help? I do not want to have to re-work my acrylic box or lite fixture too much...but I can probly reduce it to 14"x6" with out too much work if that will help.

kerry
10-25-2011, 10:16 AM
You have 160 sq" per side, so its 320 total. So you would need more light or just cut down the size.

SantaMonica
10-25-2011, 10:17 AM
No, he has 160 sq in, and 100 watts.

kerry
10-25-2011, 10:23 AM
So the sq" is not counting both sides!!!

Floyd R Turbo
10-26-2011, 01:24 PM
That's been a point of contention. We always say 1 square inch referring to the dimensions, not the area. Thus a 10 x 16 screen is 160 sq in and would need 160 watts of total light. It's less confusing than saying 320 sq in of total surface area lit by 0.5 w/sq on each side. 1W per square inch dimensional area split between each side of the screen. If it's one sided then it's technically 0.5w/sq. in. but double the dimensional area so same amount light on the same amount of surface area as a double sided screen.

kerry
10-26-2011, 01:36 PM
OK, that would explain why I stopped burning algae when I cut my lighting in half LOL!!

new2scrub
11-05-2011, 09:09 PM
my screen is now 6"x12" so 72 square inches and I have 46 watts per side. So my light is still a little low? Maybe I will try larger bulbs. Where can I get 150watt equivalent bulbs cheap?

Floyd R Turbo
11-05-2011, 09:44 PM
you're over 1W / sq in so that's good. You don't care about equivalent wattage, only actual. I don't know if you could go too much larger without spending a lot.

kerry
11-05-2011, 09:45 PM
you have 92 watts which is more then the 72 inches you have. I think you have plenty of light. Am I missing something???

kerry
11-05-2011, 09:46 PM
OK, so Floyd got his in a few seconds before mine LOL!! So I am still thinking the light thing right.

kerry
11-05-2011, 09:48 PM
Walmart had some 55Watt CFL's for under $9.00.

SantaMonica
11-06-2011, 07:39 AM
1 watt per square inch is a minimum; 2 watts is the high-wattage, low-hours, long-lifetime technique

simon wright
11-12-2011, 01:37 PM
right i have never been good with maths at all :oops: , so the way i have my scrubber now is waterfall type 1 sided light is 30w cfl bulb large screen , but with this new size guide what size do i need now? . i feed 2 cubes of frozen a day and around 3" long x 1" wide peace of nori a day . this will stay the same in the future also .
would like to cut the lighting times down also .
thanks in advance .
i would also like to go diy led on the new screen also , so how many leds and total led wattage ?

SantaMonica
11-12-2011, 02:41 PM
12 watts for 18 hours a day, 1-sided, handles 1/2 cube.
24 watts for 9 hours a day, 1-sided, also handles 1/2 cube.

Your 30 watts is a bit more than you need for 1/2 cube a day if you run it for 9 hours. But if you run it for 18 hours you can do 1 cube.

3 square inches of nori is about 1/3 cube. So you are wanting to feed a total of about 2 1/3 cubes. Thus, you do not have enough wattage. If your screen were 2-sided (with 15w on each side), it would handle twice the feeding with the same wattage.

If 30 watts is all you can use, and you have to keep it 1-sided, you'll need to run it for 18 hours to be able to feed 1 cube.

A good screen for your 30 watts would be 5 X 6, with a reflector so that all the light hits the screen.

tebo
11-15-2011, 07:07 PM
hi santa monica



1 frozen cube per day (2-sided screen)
1/2 frozen cube per day (1-sided screen)
10 pinches of flake food per day (2-sided screen)
5 pinches of flake food per day (1-sided screen)
10 square inches (50 sq cm) of nori per day (2-sided screen)
5 square inches (50 sq cm) of nori per day (1-sided screen)
0.1 dry ounce (2.8 grams) of pellet food per day (2-sided screen)
0.05 dry ounce (1.4 grams) of pellet food per day (1-sided screen)



assuming that all the ats is well conceived, can handle all this
food in one day??

Floyd R Turbo
11-15-2011, 07:29 PM
No, those are examples of the cube-equivalents of each of those types of food. Each of those lines equals one cube of food and a 12 sq in screen would handle 1 cube of food per day, or the equivalent thereof.

However if your screen is 8 x 12 = 96 sq in, then yes, you can feed each of the above amounts per day I guess.

tebo
11-16-2011, 05:04 AM
floyd thank you very much :) , by the way take your advice and reduced the size of the screen 8-)

Drewfish
11-16-2011, 01:17 PM
Ok, I'm new to this and I'm setting up a scrubber for my 36gal. I was going to do a 5x8 screen (40 sq inches) so I would need 40 watt on each side of the screen? or 20watt one on each side for a total of 40w? And I would be good on 1cube feed a day. This is a tank just starting cycle and am constructing scrubber now.

kerry
11-16-2011, 01:30 PM
You can feed 3 cubes a day and use 20W per side. It would be best to get the scrubber in there ASAP. The scrubber basically makes the tank not go through the big spike of the cycle. My nitrates never went over 5PPM when I started my 40G from day one with a scrubber.

Drewfish
11-16-2011, 02:23 PM
Great thanks kerry!!! I may reduce the wattage then and am seriously considering led's. I may just wait and see what SM comes up with with the Scrubber 2 for nano's. This tank is empty and I'm still planning things out and getting parts and pieces.

kerry
11-16-2011, 02:45 PM
I really like the LED's on my nano. I will be switching all of them soon.

bfoleyiii
12-05-2011, 06:15 AM
How much does the reflector play into the wattage necessary. I am thinking about a build of four 3x4 screens surrounding a 23w bulb. At nine hours a day would this give me about 4 cubes per day (way more than I need) or is the lack of a reflector going to lower the feeding numbers? Is the light still supposed to be 4" away from the screen or is that changed with the new screen size?

Thanks,

Bob

SantaMonica
12-05-2011, 08:57 AM
First, it's 1-sided. Second, you are losing light out of 2 of the 6 sides, so you are losing 1/3, and only getting 2/3 left over. Third, the bulb will be too close, almost touching.

Use 6 X 6 pieces, and make the box with them. It will still be 24w and 1-sided, but it will catch more light, except the top and bottom.

12w 2-sided 18-hours is 1 cube (standard example from guideline)
12w 1-sided 18-hours is 1/2 cube
24w 1-sided 18-hours is 1 cube
24w 1-sided 9-hours is 1/2 cube (same as 3/6 cube)

You will be losing one-third of your light, so you will left with two-thirds. Two-thirds of 3/6 cube is 2/6 cube = 1/3 cube. So you can feed 1/3 cube. Having open-sides really cuts into filtering. 1-sided really cuts into filtering too, compared to 2-sided.

Floyd R Turbo
12-05-2011, 10:08 AM
Also how do you propose to feed the water to the screens? With the lamp in the middle how are you going to protect it?

bfoleyiii
12-05-2011, 10:24 AM
I would build an acrylic cube to protect the light with the light dropping down into the middle. I was thinking I'd build a square out of pvc to feed the screens (a T fitting and a few 90s) on the outside of the acrylic. I was thinking that one 23w bulb could then feed the four screens equalling two 2-sided screens.

markrj
02-28-2012, 09:02 PM
Wow! This thread is an eye-opener! I just finished my first scrubber based on Floyd's Summary.

http://algaescrubber.net/forums/showthread.php?1291-Algae-Scrubber-Basics-The-Summary


Screen Size

Once you figure out your available flow, then it's time to figure out your optimal screen dimensions.

There are 2 ways of looking at this: square inches based on length and width dimension, and square inches based on illuminated surface area. The latter is technically more accurate, but since most people light both sides, the former is usually referenced.

For every gallon of water in your display tank, you need 2 total square inches of illuminated screen material. This means that if you run a screen that is vertical and lit from both sides, then you need a screen with dimensions (length times width) that is equal to the size of your tank, or 1 square inch of material per gallon. This is what you will see commonly referenced, and what I continue to reference for simplicity's sake. Double the dimensional measurement for a vertical screen, lit from only one side. Double it again for a horizontal or slanted screen.

Sizing of the screen generally does not require inclusion of the volume of water in the sump, unless you have some kind of bio-load in there, like a refugium for a recovering fish, pods, or a frag tank, etc.

So, just so we're 100% clear on this:

Vertical, lit from both sides: 1 square inch of screen material per gallon (2 square inches of illuminated screen area per gallon)

Vertical, lit from only one side: 2 square inches of screen material per gallon (which is also 2 square inches of illuminated screen area per gallon)

Horizontal: 4 square inches of screen material per gallon (4 square inches of illuminated screen material per gallon). Lighting must increase by a factor of 1.5 (discussed in the lighting section). Also note that this is a correction to what was listed on Post #1 of this thread (that post listed that a 10 x 10 screen was good for 40 gallons, instead of 25 gallons)

I am running a 12" wide x 10" (1-2" in the water.) which is 96 sq in of exposed screen. Two sided so I am seriously over sized and under wattage. Correct?

I have a 75 gallon reef with just 3 fish which I feed about 1/4 of a frozen cube per day. I had a horrible cyano and gha problem and it is all disappearing before my eyes with my new setup after only 7 days. I am going to do my first cleaning tomorrow after the full 7 days are up.

So I could seriously use a 6"x4" screen?

Time to cut a new slot pipe! lol

SantaMonica
02-29-2012, 09:02 AM
Yes way too big. You can use a tiny screen, limited only by it catching all the light.

iprayforwaves
03-11-2012, 09:44 PM
SM,

how does feeding live foods such as decap. artemia cysts, baby artemia and rotifers compare to the frozen cube guideline?

SantaMonica
03-11-2012, 09:48 PM
You'll have to concentrate them and put them in an emtpy cube to see how many there are.

Floyd R Turbo
03-12-2012, 07:48 AM
In other words, use a rotifer sieve to take out all the water. I would think you could feed a cubic buttload of rotifers to equal 1 cube/day.

Salty Irishman
03-14-2012, 12:33 PM
Great site and I'm new here. Congrats to all who have contributed and thank you! I just got my scrubber up and running however, it's based on the old formula of tank size. Now I realize I can go way smaller which is a plus when you're out of room in the sump. So based on my needs I'm looking at a 3" x 4" screen. Question is; what type of lighting is recommended to focus on such a small screen and at 6-12 watts/side? Right now I'm running (2) 23 watt cfl's and have had to cut the hrs back as I'm getting some yellowing. I can build another scubber easy enough, but the lighting is my hang up. Thoughts...

kerry
03-14-2012, 12:59 PM
Spot light CFL's work the best on small screens.

Floyd R Turbo
03-14-2012, 01:23 PM
It's my preference, but I think a 2 cube/day screen is really a minimum, unless you know for sure that you're not going to feed any more than 1 cube/day. so 5x5, which is a nice fit for a 23W CFL floodlight on each side.

the yellowing is because your screen is too large in relation to the feeding. 5x5 should green it up, but you may have to feed a little more, which your tank will like :)

submersible
03-21-2012, 02:08 PM
Just curious, does a protein skimmer have any effect on the screen size?

SantaMonica
03-21-2012, 03:24 PM
Not really.

jaws
03-31-2012, 09:18 PM
I don't quite understand what you mean by real watts, not equivalent. Does that mean you can't use the energy efficient bulbs or you can but make sure you use the real wattage when buying the bulbs instead of the equivalent watts?

SantaMonica
04-01-2012, 03:59 AM
You can use them but calculate using the real and not equivalent.

jaws
04-01-2012, 07:53 AM
Excellent. Thanks. Do you have to worry about heat at all? I built my scrubber out of an old CPR aquafuge and I'm curious how hot the bulbs get close to the acrylic.

SantaMonica
04-01-2012, 10:34 AM
I don't think so.

rygh
04-15-2012, 05:08 PM
New Scrubber Sizing Guideline (Sept 2011)
HORIZONTAL screens: Multiply the screen size by 4, and the wattage by 1.5

I generally like your new guidelines, since it is pretty clear my scrubber is over-sized.
But I do have a problem with that statement from my experiments with horizontal scrubbers.
I actually feel the recommendation should simply be: Don't do a horizontal scrubber.
The problem is not so much size/lighting, is that the algae cannot grow up away from the screen
properly, and do not have max-efficiency to really out compete the algae in the main tank.

Don't get me wrong. I know that horizontals do work. And certainly reduce nitrates.
But I feel you should keep the message simple. Promote what is clearly best : Vertical waterfall.

And to be honest, I think the horizontal issue is why a lot of old scrubbers had issues in the past.

joelespinoza
04-21-2012, 07:45 AM
I think it is kind of understood horizontal scrubbers are not optimal, however sometimes you do what you have room for. That being said I believe the reason you want to have 4x the screen size is the very reason you listed, the algae cant grow up very far so it has to spread out.

A grass lawn needs more surface area to take up the same nutrients a forrest does, it just makes sense.

djmatteo
04-27-2012, 11:35 AM
Perhaps I could get some guidance on my rebuild.. I recently adopted an algae scrubber with a 10.5 x 13" screen (way to big and expensive to light), I adapted it to my aquarium by gravity feeding it from my 125 g tank above in the dining room. It has two ~50 watt CFLs with reflectors on both sides. The acrylic is half moon cut to fit the reflectors on the sides. (link to facebook is picture of it)
http://www.facebook.com/media/set/?set=a.10150165685667306.354011.593277305&type=3#!/photo.php?fbid=10150923916432306&set=a.10150165685667306.354011.593277305&type=3&theater

Even though I am gong to rebuild, the problem with this scrubber currently is I can not open my ball valve from above all the way. I get tiny air borne water bubbles which get the reflectors and bulbs wet. I did put a bead of silicone around the base of the bulbs, but its still just risky. The bubbles seem to come primarily out of the slot, but I believe some also are coming from the tank below. Any suggestions to fix this design, perhaps make the slot a tiny bigger? Wouldnt mind fixing the bubbles in the meanwhile so i can increase flow, im tired of the big yellow spot in the middle!

ok, but now to the brass tax. Regardless of above scrubber, I need to rebuild. I want to make sure I understand all this...

a 3x4 2 sided screen would need 12 watts per side, and scrub approx 1 frozen cube per day. I would like to be able to handle at -least- 2 frozen cubes per day so I would need to double my screen size, 4x6 and run 24 watts per side.

Questions...
Does putting the CFLs outside the acrylic and not directly next to the screen impact growth?

How do you calculate screen sized based on your bio load or anticipated stocking?

Would it be wise if I anticipate heavy fish stocking that I go with a bigger screen from the start, or by not feeding approximately what the scrubber was built for will the algae not grow as well and thus not filter as well.

Thanks in advance, if anyone has plans for a box of this sort that would sit on a 55 gallon sump im all ears and eyes. Thanks so much!

kerry
04-27-2012, 11:42 AM
Check out this link for sizing: http://algaescrubber.net/forums/showthread.php?1419-New-sizing-guidelines . I cannot the link to work.

Floyd R Turbo
04-27-2012, 11:46 AM
Minimum is 12 total watts per 12 sq in, so you could go 12w on each side of a 24 sq in screen, but 24 per side would be better. If all that light is "captured" by the screen, then you can go 1/2 time on the photoperiod (9 on). If not, you can probably still reduce it until you get green instead of yellow (which is too much light per nutrient delivered).

Acrylic shields will not block light significantly enough to impact growth. Acrylic is clearer than glass so you're good to go there.

Bio-load and stocking calcs have no meaning for sizing a scrubber. Only feeding as the input.

I would only oversize the screen by 50% max and then feed at that level. As you add fish, feed the same amount. Marine fish can go 3 days without food so feeding them less daily will do just fine, and when your quantity of fish increases to the point where you wish to feed more, then you can add to the scrubber. This will likely be months or possibly a year or so down the road as you stock your tank and your fish grow. Also you might be able to just extend the photoperiod a bit (if you're running 9 on) to compensate for additional feeding, but this may only work to a certain point.

As for your original problem, just drape Saran Wrap over the tube and extend it about 1" down on either side of the screen, and all your spray problems will disappear. You can also drape the entire screen in saran wrap and do away with the acrylic shield completely.

Floyd R Turbo
04-27-2012, 11:47 AM
Um, kerry, that's this thread LOL

djmatteo
04-27-2012, 11:48 AM
Thats the link to this thread, I have read in fact I started with the same sized screen as mentioned in the summary. I just want clarification, and also I have other questions than just screen size. I have been scrubbing for like 2 weeks, I am the guy that always does things wrong the first time, so I want to make sure I get it right the second time and possibly correct my current scrubber issue.

kerry
04-27-2012, 11:52 AM
Um, kerry, that's this thread LOL
This is the FIFTH Monday in a row, I cant wait until its &^%^%* Friday!!!!!! LOL, my bad. Sorry guys. Good catch.

djmatteo
04-27-2012, 11:58 AM
Thanks Floyd, I do believe you answered my questions. I saw another thread where a guy had saran wrap on his scrubber but I wasnt sure that was an approved way of fixing the bubble problem.

In a round about way I think you also gave me a pointer to reduce my lighting to get some better growth. I feed pretty light currently, and my algae over 7 days is more of a slimy kind of stuff of various colors (ive got hair in my sump now in small amounts). But between bulbs being about 3 months old, restricitng flow, and not enough watts per each side of the screen I had a few factors hindering growth. I think this week I will feed slightly more and reduce lighting and see what happens.

I think when I do my final calculation on my screen I will do some bulb shopping and find out where that price jump is!

Floyd R Turbo
04-27-2012, 12:19 PM
Also you can read through the latest iteration of the Basics here http://algaescrubber.net/forums/showthread.php?1291-Algae-Scrubber-Basics-The-Summary (written by yours truly). Go to the Feb 17th post for the current guidelines. Everything there should really be followed, the slot straightness and correct width, screen roughness, flow, don't cinch zip ties down hard (pinches the slot), light temp, etc. Review that and see if anything pops out at you.

thatgrimguy
05-02-2012, 06:48 PM
What is the sm 100 rated for under these guidelines? Still roughly 10 cubes?

kerry
05-02-2012, 06:51 PM
Not sure the screen size right off but its 1 cube per 12" of screen.

SantaMonica
05-02-2012, 06:54 PM
10 cubes when growing 3D

dryworm
06-03-2012, 11:46 PM
if i build a uas in the sump lighted on one side. a reflector on the the other side. does that count as a one sided screen or a two sided screen?

Floyd R Turbo
06-04-2012, 10:27 AM
Yes, if the light has to pass through the screen to get to the other side. Once algae grows thick enough, no light will be transmitted and therefore none reflected.

dryworm
06-04-2012, 12:38 PM
so if i am building a uas similiar to the hog. at one cube a day. i would need a 6 x 8 screen and 12 watts of leds or 24 watt cfl at 18 hours a day. sorry if this seems obvious but i want to make sure.

kerry
06-04-2012, 12:52 PM
Normally you only need a 1/4 it a 1/3 of LED wattage compared to CFL.

dtyharry
06-04-2012, 01:29 PM
Surely one sided needs 24sq in so 6x4 inches would be fine with 24w cfl

dryworm
06-04-2012, 05:29 PM
ah ok. the example had 3 x 4 for a .5 cuble. so i doubled it to 6 x 8. i see my error now thanks. i seen sm's hog design and it was a 12 watt cfl and a 6w led. thats how i figured it was half. i will be using a dimmable led driver so i can adjust accordingly. thanks for y'all help.

Floyd R Turbo
06-04-2012, 07:39 PM
Don't dim, just go less hours. If you go by the minimum LED 'guideline' of one 3W LED per 16-20 sq in (4x4 to 4.5x4.5) this is especially true, IMO

sklywag
06-04-2012, 08:33 PM
Wow! I'm thinking of using LEDs on my new ATS. I PMed you about that by the way Floyd. So only one(1) 3 watt LED for a 4x4 inch screen? How far away? Bright white? Soft white? 6500K?

What if you use a lesser watt LED? I see a lot of reds being used with some blues. Is there a dominant pattern that seems to work best?

Floyd R Turbo
06-04-2012, 10:19 PM
I must have missed the PM? Use 660nm deep red primarily, you can add a blue 455 and WW maybe too, but you should have roughly 6:1 red : other, or somewhere near that ratio. 1 3W per 4x4 is what I consider the minimum. I actually build them with 4x the density, one every 2x2 (on each side) and then add a diffuser to blend. Diffuser is something I added standard to my builds (new post coming soon, one of these days...)

SantaMonica
06-06-2012, 05:39 PM
if i build a uas in the sump lighted on one side. a reflector on the the other side. does that count as a one sided screen or a two sided screen?

Depends on how the reflector is set up. If it is oversized and spread out well beyond the screen, and angled so that light can get around the back side, and if the light can get around the screen, it might be possible to approach a 2-sided screen.

pskelton
06-27-2012, 04:31 AM
If this has already been answered I apologize, with the new sizing guidelines is there an estimate for say teaspoons of pellet food per square inch of screen. I know I feed my tank a couple good pinches of food per day but I don’t know how that transfers to ounces. If I had a measuring spoon per square inch estimate It would be helpful.

kerry
06-27-2012, 04:58 AM
I would say a teaspoon is going to be very close to a cube as a teaspoon is 5ml. I was trying to find the exact ml to a cube but I cant find it.

MorganAtlanta
06-27-2012, 02:35 PM
But frozen food is 90% or more moisture, so it is hard to say. Assuming 90%, a 3.5g cube of frozen food would really only contain about 350mg of actual food. That's probably the better number to compare against flake or pellets rather than trying to compare volume since they are all different densities.

djmatteo
08-01-2012, 10:43 AM
http://algaescrubber.net/forums/showthread.php?2135-Sizing-opinions-needed

Cole
09-23-2012, 08:32 AM
Right now i have a 210 gallon tank and i feed 3 cubes a day and put in 2 sheets of nori daily. Would a 6 by 10" long screen be okay if a had two 23watt cfl lights on each side
Thanks.

Garf
09-23-2012, 08:47 AM
Right now i have a 210 gallon tank and i feed 3 cubes a day and put in 2 sheets of nori daily. Would a 6 by 10" long screen be okay if a had two 23watt cfl lights on each side
Thanks.

Any chance of making it 12 or 13 x 6 or 7 ? That would definitely be big enough, and maybe easier to utilise the lights potential.

Cole
09-23-2012, 08:50 AM
ya that would work i've got plenty of room to build it in. so does 7by 12 sound good

Garf
09-23-2012, 08:56 AM
ya that would work i've got plenty of room to build it in. so does 7by 12 sound good
Sounds like your feeding about the same as me, and mine is about that size, and it works! Be good to start a new build topic on here, you'll get everyone's help to max its potential.

acorral
10-01-2012, 08:33 PM
I made an 8 inch wide red led ats

Mesured the flow at 551 gph so its almost 69 gph per inch

Is that too much flow? Should i dial that down a little bit?

tebo
10-01-2012, 10:30 PM
Much flow is always better, but please note that if you have a lot more light you handle flow

More flow is always better than less flow

You measure the color of the alga, she'll tell you if you need more light or not

regards

Floyd R Turbo
10-02-2012, 08:50 AM
That's a lot of flow IMO. The algae will have to be pretty well anchored to the screen.

Midway
11-12-2012, 12:41 AM
Hi guys, I'm new here and definitely i want to build an ATS here. I've been battling high nitrates for so long that's not even funny but I want to keep my fish and corals well fed. What if I want to feed 4 cubes and a sheet of nori every day? How wide and how long would I have to build my ATS? And what'd be the wattage i'd need to light the sheet?

Thanks for your help guys!!

acorral
11-12-2012, 05:02 AM
Hi guys, I'm new here and definitely i want to build an ATS here. I've been battling high nitrates for so long that's not even funny but I want to keep my fish and corals well fed. What if I want to feed 4 cubes and a sheet of nori every day? How wide and how long would I have to build my ATS? And what'd be the wattage i'd need to light the sheet?

Thanks for your help guys!!

That would be around 8 cubes....

2 sided 10" x 10" with 100 watts CFL

Midway
11-12-2012, 01:06 PM
Thanks very much for the reply. Well i don't give them 2 nori sheets everyday, but i'm counting the food I give to my eel, which i give him 2 or 3 peices of squid or shirmp plus i dose some micro algea in the tank no and then. So yes thanks for the advice i think 10" X 10" with 100 cfl lights would do the trick. I'm excited to give this a try to see if my nitrates come down to acceptable levels.

thatgrimguy
11-13-2012, 03:29 PM
based on these guidelines, and just based on the screens size, what is a santamonica 100 rated for food wise?

SantaMonica
11-13-2012, 04:56 PM
10 cubes

HK_Fuey
02-28-2013, 05:07 PM
Flow is 24 hours, and is at least 35 gph per inch of width of screen [60 lph per cm], EVEN IF one sided or horizontal.
I'm just trying to design my first ats. It seems from this statement, I would need a smaller pump if I design for a long, thin screen, rather than a short, wide screen. Is that right?

Also, I've heard about 3D ats. Are there further guidelines around this?

SantaMonica
02-28-2013, 06:57 PM
Welcome.

Correct.

3D just requires a box for the growth to get thick in.

danbonk
04-04-2014, 07:51 PM
Hi,
just worked out the size for a screen lighting from 2 sides for feeding 2 cubes per day and got the numbers 3"x8" with 105 gph min flow and 12w (actual) for 18h per day, or 24w each side for the wattage technique ?. Just wanted to know if anyone could tell me if this is correct please.

SantaMonica
04-05-2014, 07:04 AM
Welcome from UK.

Yes 12w each side minimum, 24w each side high. Flow is correct if you are hanging it vertically like a ladder.

danbonk
04-05-2014, 02:07 PM
Thank you for your speedy reply and confirming that for me i can start getting this underway.

SantaMonica
07-27-2014, 11:26 AM
What size scrubber do you need?
(edited July 2014)

The basic guidelines for algae scrubbers is based on how much you feed each day: 1 cube a day, 2 cubes a day, etc. However these are just starting points; a lot of your tank filtering is based on your rocks, so their condition plays a part too in what size scrubbers to get or make, as well as what type of feeding you are doing, and what other filters you will be using. This calculator is the starting point:

https://public.sheet.zoho.com/public/cdm2013/ascalculator-xls-1

...and here is a description:

Scrubbers are sized according to feeding. Nutrients "in" (feeding) must equal nutrients "out" (scrubber growth), no matter how many gallons or liters you have. So...

An example VERTICAL upflow or waterfall screen size is 3 X 4 inches = 12 square inches of screen (7.5 X 10 cm = 75 sq cm) with a total of 12 real watts (not equivalent) of fluorescent light for 18 hours a day. If all 12 watts are on one side, it is a 1-sided screen. If 6 watts are on each side, it is a 2-sided screen, but the total is still 12 watts for 18 hours a day. This screen size and wattage should be able to handle the following amounts of daily feeding:

1 frozen cube per day (2-sided screen), or
1/2 frozen cube per day (1-sided screen), or
10 pinches of flake food per day (2-sided screen), or
5 pinches of flake food per day (1-sided screen), or
10 square inches (60 sq cm) of nori per day (2-sided screen), or
5 square inches (30 sq cm) of nori per day (1-sided screen), or
0.1 dry ounce (2.8 grams) of pellet food per day (2-sided screen), or
0.05 dry ounce (1.4 grams) of pellet food per day (1-sided screen)

High-wattage technique: Double the wattage, and cut the hours in half (to 9 per day). This will get brown screens to grow green much faster. Thus the example above would be 12 watts on each side, for a total of 24 watts, but for only 9 hours per day. If growth starts to turn YELLOW, then increase the flow, or add iron, or reduce the number of hours. And since the bulbs are operating for 9 hours instead of 18, they will last 6 months instead of 3 months.

HORIZONTAL screens: Multiply the screen size by 4, and the wattage by 1 1/2. Flow is 24 hours, and is at least 35 gph per inch of width of screen [60 lph per cm], EVEN IF one sided or horizontal.

FLOATING SURFACE SCRUBBERS WITH RIBBONS: Screen size is the size of the box (Lenth X Width), and is 2-sided because the ribbons grow in 3D.

LEDs: Use half the wattage as above. 660nm (red) is best. You can mix in a little 450nm (blue) if you want.

Very rough screen made of roughed-up-like-a-cactus plastic canvas, unless floating surface, which would use gravel and strings instead.

Clean algae:

Every 7 to 21 days, or
When it's black, or
When it fills up, or
When algae lets go, or
When nutrients start to rise


HOWEVER, your rocks can supply much more "feeding" to your water that the actual food you put in, because rocks absorb phosphate, and once the rocks are "full" they will put this phosphate back into your water, adding to the phosphate that you are feeding. So the above sizing guidelines need to be modified in certain situations:

1) If you are building a reef tank which is new, meaning that the rocks are coming from the ocean or from a low-nutrient tank, and if you will just be feeding the fish sparingly, and if you DO want to have other filters and water changes, then you can just use the cube-feeding recommended sizes of the scrubbers.

2) If you are building a reef tank which is new as in #1 above, but you DON'T want any other filters or water changes, then double the recommended scrubbing amount in #1. This will supply the corals and small fish with the most amounts of food particles. You don't need to start the tank with all the scrubbers; one is fine for a few months. Add the others later.

3) If you are building a reef tank which is new as in #1 or #2 above, but the rocks are coming from a nutrient-problem tank which had measurable phosphate or hair algae problems, then the rocks will be soaked with phosphate and this will supply more phosphate to your new tank than the feeding will. So double the recommend scrubbing amount. And if it is a new reef tank with problem rocks AND you don't want other filters or water changes, you would need four times the scrubbing in order to handle the problem rocks and the other filters.

4) If you are adding a scrubber to an existing reef tank, and the tank has no measurable phosphate and no nuisance algae, and if you have other filters and water changes and you DO want to keep them, then you can just use the cube-feeding sizes of the scrubbers.

5) If you are adding a scrubber to an existing reef tank as in #4 above but you DON'T want to continue using the other filters or water changes, then double the scrubber amount recommend in #4, preferrably with an additional scrubber. This will keep filtering going in one when you clean the other.

6) If you are adding a scrubber to an existing reef tank that has measurable phosphate and green hair nuisance algae on the rocks, and you DO want to continue using other filters and water changes, then you can just use the recommended cube-feeding sizes of the scrubbers. Use stronger light if possible because the higher phosphate in the water needs brighter light to make the scrubber grow green. And if you double the amount of scrubbing (two scrubbers instead of one), the problems will clear up twice as fast because there will be twice the amount of algae absorbing the nutrients out of the water.

7) If you are adding a scrubber to an existing reef tank that has measurable phosphate and green hair nuisance algae on the rocks as in #6 above, and you DON'T want to continue using other filters and water changes, then double the amount of scrubbing recommended in #6.

8) If you are adding a scrubber to an existing reef tank that has NO measurable phosphate, but has LOTS of green hair nuisance algae on the rocks, then you need the strongest lights possible (for your scrubber size) because the rocks are already full of phosphate, and the algae on the rocks is absorbing this phosphate, meaning you need the strongest scrubbing possible in order to out-compete the algae on the rocks. This is the hardest situation to fix, so you should use as much scrubbing as possible with the strongest light available (for the scrubber size), and use as many other filters and water changes as possible too, until the algae on the rocks turns yellow and lets go. At this point coralline will start to cover the rocks, and you could consider selling some of the extra scrubbers, or removing the other filters or water changes.

End

andi
06-11-2017, 08:36 AM
the link for the size calculator is broken, can you please make another one? thanks

SantaMonica
06-11-2017, 06:28 PM
Welcome, and thanks for noticing. Actually the person who made that one recently made another one to replace it, but it was not working correctly yet. So hopefully one day it will be fixed.

SantaMonica
08-18-2017, 03:09 PM
Any scrubbing is good scrubbing. Even a small algae scrubber on a big tank will help your glass stay clearer, longer. But beyond that, the basic guidelines for algae scrubbers are based on how much you feed each day. These guidelines are to help you get the minimum size or number of scrubbers that will still do a good job of total filtration. You cannot "over scrub", so having a larger scrubber (or more of them) simply works more like the oceans and lakes do which have enormous amounts of algae to do all the filtering. And the scrubber can go anywhere in your system; it will filter the same.

Scrubbers are sized according to feeding. Nutrients "in" (feeding) must equal nutrients "out" (scrubber growth), no matter how many gallons or liters you have. So...

An example VERTICAL upflow or waterfall screen size is 3 X 4 inches = 12 square inches of screen (7.5 X 10 cm = 75 sq cm) with a total of 12 real florescent watts (not equivalent watts) of light, or half that for LEDs, for 18 hours a day. If all 12 watts (6 watts LED) are on one side, it is a 1-sided screen. If the watts are divided on each side of the screen, it is a 2-sided screen. This should be able to handle the following amounts of daily feeding:

1 frozen cube per day (2-sided screen), or
1/2 frozen cube per day (1-sided screen), or
10 pinches of flake food per day (2-sided screen), or
5 pinches of flake food per day (1-sided screen), or
10 square inches (60 sq cm) of nori per day (2-sided screen), or
5 square inches (30 sq cm) of nori per day (1-sided screen), or
0.1 dry ounce (2.8 grams) of pellet food per day (2-sided screen), or
0.05 dry ounce (1.4 grams) of pellet food per day (1-sided screen)

Problem rocks: Each 50 pounds (2.2 kg) of nuisance algae covered rocks you have adds 1 cube a day.

Flow or air bubbles is always 24 hours; water flow is at least 35 gph per inch of width of screen [60 lph per cm], EVEN IF one sided or horizontal.

Floating surface scrubbers with strings: Screen size is the size of the box (Length X Width), and is 2-sided because the strings grow in 3D.

Clean algae:

Every 7 to 10 days, or
When it's black, or
When it fills up, or
When algae lets go, or
When nutrients start to rise

However these are just starting points; a lot of your tank filtering (especially in saltwater) is based on your rocks, so their condition plays a part too in what size scrubber to make, as well as what type of feeding you are doing, and what other filters you will be using. Here are some specific guidelines:

FRESHWATER:

Since freshwater grows extremely thin, long algae, scrubbers without strings are recommended. This is because you will probably need to clean the scrubber in your sink with a toothbrush (instead of in-place harvesting while still in your aquarium), and it's easier to brush a flat wall than it is to brush strings. So flat-wall scrubbers such as wide-panel bubble upflows work well in freshwater. Also, since the thin stringy freshwater algae will flow out of holes in the scrubber, if you put the scrubber in your display (where the animals are), they will learn to eat out of the scrubber and you will therefore be able to feed less. If you intend to do a large part of your feeding this way, multiple scrubbers will allow the feeding (and filtering) to continue in one when you have cleaned the other. Waterfall types are not recommended for freshwater because the long thin growth flows out of the drain.

SALTWATER:

With saltwater, you can get thick dense growth in the scrubber, which is when strings are an advantage (to hold on to the growth). So adding strings to a scrubber is acceptable and the decision is based on size and on where you want to put it, and also on how you want to clean it. Saltwater tanks which use live rock (even if the rock is "dead") will need to take into consideration the history of the rock: If it came from a tank with algae problems, each 50 pounds (23 kg) of this rock will add 1 cube a day to your feeding. This is because the rock is really just coral skeletons which absorbed nutrients from the water when the nutrients in the previous (or current) tank were high, and these nutrients will then start coming out and flowing into the water when your scrubber starts working.

After looking at size, the main consideration is where you are going to put it. Since scrubbers filter the same in any location, it is just a matter of placement. Unlike freshwater, the thicker growth in saltwater usually does not flow out of the holes or drains as much, so you can't rely on it for automatic feeding (although you can manually take some growth out, and feed that). And similar to freshwater, multiple units are better than a single unit.

REEF:

Reefs are the same considerations as saltwater, with the exception that some people like the reef to run as natural as possible, meaning filtered by algae alone. With that in mind, here are some more details and options:

1) If you are building a reef tank which is new, where the rocks are coming from the ocean or from a low-nutrient tank with no algae problems, and if you will just be feeding the fish sparingly, and if you DO want to have other filters and water changes, then you can just use the cube-feeding recommended sizes of the scrubbers.

2) If you are building a reef tank which is new as in #1 above, but you DON'T want any other filters or water changes, then double the recommended scrubbing amount in #1. This will supply the corals and small fish with the most amounts of food particles, and will allow filtering and feeding to continue in one scrubber after you have cleaned the other.

3) If you are building a reef tank which is new as in #1 or #2 above, but the rocks are coming a nutrient-problem tank which had measurable phosphate or hair algae problems, then the rocks will be soaked with phosphate and this will supply more phosphate to your new tank than your feeding will. So use the 50 pounds of rock = 1 cube of feeding guideline, to add to the recommend scrubbing amount.

4) If you are adding a scrubber to an existing reef tank, and the tank has no measurable phosphate and no nuisance algae, and if you have other filters and water changes and you DO want to keep them, then you can just use the cube-feeding sizes of the scrubbers.

5) If you are adding a scrubber to an existing reef tank as in #4 above but you DON'T want to continue using the other filters or water changes, then double the scrubber amount recommend in #4, preferably by having multiple scrubbers which are cleaned alternately. This will keep one scrubber filtering and feeding when you have cleaned the other.

6) If you are adding a scrubber to an existing reef tank that has measurable phosphate and green hair nuisance algae on the rocks, and you DO want to continue using other filters and water changes, then you can just use the recommended cube-feeding sizes of the scrubbers. Use extra light (more LEDs) if possible because the higher phosphate in the water needs brighter LED's to make the scrubber grow green sooner. And if you double the amount of scrubbing (two units instead of one), the problems will clear up twice as fast because there will be twice the amount of algae absorbing the nutrients out of the water, especially when you clean one of them.

7) If you are adding a scrubber to an existing reef tank that has measurable phosphate and green hair nuisance algae on the rocks as in #6 above, and you DON'T want to continue using other filters and water changes, then double the amount of scrubbing recommended in #6.

8) If you are adding a scrubber to an existing reef tank that has NO measurable phosphate, but has LOTS of green hair nuisance algae on the rocks, then you need the strongest LEDs possible because the rocks are already full of phosphate, and the algae on the rocks is absorbing this phosphate, meaning you need the strongest scrubbing possible in order to out-compete the algae on the rocks. This is the hardest situation to fix, so you should use as much scrubbing as possible with the strongest LEDs available, and use as many other filters and water changes as possible too, until the algae on the rocks turns yellow and lets go.

End

markstrimaran
12-06-2017, 09:59 AM
How many grams of 1.5mm pellets are in a teaspoon?

SantaMonica
12-06-2017, 08:43 PM
About 1 gram.

SantaMonica
05-12-2019, 02:27 PM
NOTE2: This calculator might help, if it is still working:
https://docs.zoho.com/sheet/published.do?rid=b0tmj6d91ce368ee542aba6b2b670ae00 412b

SantaMonica
11-21-2022, 08:01 PM
Updated