My first scrubber!

[steve]

Hi everyone,

Great site, been reading about the scrubbers for over a week now and am very interested in going down this route to solve my nitrate/hair algae on rock issue using natural means.

I'll start with a bit of background.

Tank is a 5 x 2 x 2 with approx 55kg rock, sump with chaeto in 24/7 lit fuge. In addition I'm running carbon, skimmer and fluidised rowaphos. I like my fish so am in to the very well stocked side of things. I've always struggled with cyno in the 3.5 years of the tank being in existence and whilst the cyno went 6 months ago, this was replaced by hair algae and lots of it. So much so I've removed all corals except my nem and some hair mushrooms. I started experinmenting with vodka and sulfur reactor but to no satsifactory results which leads me to this site!

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2 weeks ago I did think I'd got my nitrates just about under control as these were reading 10. So I began a process of removing all the hair algae on the rocks (lights out and physical removal) as well as increasing the flow from powerheads (now 12000lph and 6000 lph in addition to reef flsuh system of theoretical 6000lph). This worked at a treat at removing the hair algae, unfortuntately what I didnt relasise was I hadnt solved the underlying nitrate problem and within a week nitrates were at >25. At this point, panic, increase light periods, cut back on feeding to get the algae to grow back on the rocks again!!!

So here I am. Since I'm not a great DIYer, I started to prep my tank to take a scrubber as well as build my first one knowing full well it will need modification to get it where it should be. So last week was spent getting the sump unit ready to take a scrubber and yesterday was adding all the fixings and the scrubber itself.

Current tank stats:

Tank size: 5 x 2 x 2 with approx 55kg of rock. Estimated display capacity including rock displacement 450 litres
Sump size 3 x 1.5 x 1.5 holding approx 100 litres
Total system size c. 550 litres

Nitrates currently at 25 (salifert)
Phosphates registering very slight tinge of blue on salifert ie just above 0.00

Feeding regime: large pinch of flake in the morning along with approx 15 pellets. In the evening 1 cube of frozen mysis supplemented with a couple of small pieces of prawn or mussell and approx 2" square of seaweed sheet.

Current scrubber:

Width (36cm) x length (30cm) using 7 count roughed up plastic canvas
Lit on both sides with 20W spiral CFL (ie 2 light in total) with home made reflectors.
Pump is rated at 1000lph but at the required head height I'm getting 456lph.

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Please can you advise optimum screen size and flow rates so i know whether I should keep pump and reduce screen size or keep screen about the same and get a new pump?

Any feedback welcome!

Thanks,

Steve.

[steve]

Ok, so where I'm getting stuck is:

Lets assume my dailing feeding is 3 cubes a day. So does this mean:
I need 36W which would be width 8cm (3") x length 30cm (12") = 36sq" or 36"?
Given a screen width of 8cm I need 480lph @ 60lph/cm, therefore my pump is more or less there?
I need 36W of light in total, so 2 x 20W is sufficient?

I would love my assumptions to be correct and I onlly need to adjust the screen size! Please can someone let me know?

Many thanks,

Steve.

[Ace25]

In inches, your screen is 11.8"x14.2".. that seems right on the edge of needing 2 CFL bulbs per side if you use 23/26w bulbs. 1 42w bulb may suffice but 2 23w would be better.

Biggest problem I see that would make your scrubber not work at its peak potential is your lighting. Your losing 50% of your light out the sides of the bulb. You either need a reflector that will wrap around the bulb (most ideal method) not just some foil behind the bulb, or buy some 23/26w CFL spotlights, or use the dome type reflectors on the curly-Q bulbs (probably the last choice out of the 3).

Are you really only feeding 3 cubes a day on a 150G tank?

You're going to want to pull as much of that algae out of the display by hand/brush, it will make the process of getting the tank back to good condition happen much faster than just waiting for a scrubber to do that much work for you.. a scrubber can eventually handle it, but it could take a year or more from that I see in the picture if you don't manually help it along by removing as much as you can by hand. Even better, I see no reason you can't remove 1 rock at a time and scrub off all the algae in a bucket of saltwater, then put back into the display and repeat. Some tanks with corals encrusting between rocks makes that option not possible, but from your pictures it seems like you could do that, at least for the majority of the rocks.

[steve]

In inches, your screen is 11.8"x14.2".. that seems right on the edge of needing 2 CFL bulbs per side if you use 23/26w bulbs. 1 42w bulb may suffice but 2 23w would be better.

Biggest problem I see that would make your scrubber not work at its peak potential is your lighting. Your losing 50% of your light out the sides of the bulb. You either need a reflector that will wrap around the bulb (most ideal method) not just some foil behind the bulb, or buy some 23/26w CFL spotlights, or use the dome type reflectors on the curly-Q bulbs (probably the last choice out of the 3).

Are you really only feeding 3 cubes a day on a 150G tank? If so, your screen to large, by probably a factor of 10. LOL

Thanks for your reply :-)

The equivalent of feeding 3 cubes a day is about right (absolute max is 4), and the fish aren't on the skinny side! So if we start with the screen size, are we defintely saying that it is way too big? What size are we saying? Would a screen width of 3" by 12" length do the job if lit on both sides? It just seems tiny?

In terms of lighting, I was struggling to find a suitable reflector here in the UK. If anyone could send me a link or even give the name of something that would do the job, that would be excellent.

I'm pretty sure the flow on the current screen is knowhere near enough...but if I could get clarification of the screen size first and work from there that would be appreciated.

Steve.

[Ace25]

ok, I was a little off with the "factor of 10" comment, but it seems with your setup going off the "feeding guidelines", a screen size of 9"x12" is plenty, or 23cm x 30.5cm, and your correct, 36w per side is the ideal # but 2x 23w would work even better.

I never really did the math with the new guidelines before now... some reason I pictured the screen size to be MUCH smaller. Reason I think that is I run a 10"x12" screen and I feed well over 10 cubes a day of food on my 75G and the screen handles it without any problems (but I use mostly 660nm LEDs). I think those "feeding guidelines" error on the side of caution by a lot (which is always good to error that direction, but it seems to really lean towards the safe side). From my testing with LEDs, I have concluded I could cut my screen size down to 6"x8" and still be able to handle 10 cubes a day when using LEDs for lighting, which if I went off the guidelines I would need a 30"x40" screen, which coincidentally seems to follow the same power savings you get with LEDs vs conventional methods (LEDs take 1/5th the power of CFL/T5HO, and it seems the screen size is also 1/5th the size, learned something new today). That is not "official", just something that my testing has proven to me and what I will be going with on my next ATS... but anyway.. you're not using LEDs so go by the first sentence to be safe. :)

[steve]

From the new sizing guidelines, if I'm reading correctly, 9" x 12" is too big. Shouldn't it be width 3" x 12" length lit on both sides to maximise available flow and light? I don't want to have a bigger size than necessary as this just means I need more flow and more light, right?

[DennisC]

Hi Steve.

I am using CFL's with reflectors. If you look on the bay and search Hydroponics lighting, you will find them complete with bulb holders.

Dennis

[Ace25]

From the new sizing guidelines, if I'm reading correctly, 9" x 12" is too big. Shouldn't it be width 3" x 12" length lit on both sides to maximise available flow and light? I don't want to have a bigger size than necessary as this just means I need more flow and more light, right?

ya, way to early on a Sunday morning for my brain to figure out such basic math. LOL. Now the guidelines seem much more realistic after you pointed out my error.

You are correct, 3"x12" double sided seems to be correct for 3 cubes. I was tripling both dimensions, I only needed to do one. Bigger screen horizontally would require more flow, making it 3"x12" wouldn't need as much flow as say 9"x4" since the slot/flow part is so tiny (@ 3"). You could do 4"x9" if 12" tall was a space issue on your setup.

[steve]

No worries mate :-)

I have 12" clearance in my sump from pipe to water so will go with the smaller width and save the hassle of having to buy a new pump for the extra flow I'll need. Just need to get the reflectors sorted and I'm away!

That said, I'm already seeing algae discolouration on the current scrubber and its only 24 hours old!

[SantaMonica]

I would do a 4 X 12 screen, with two (2) 33w CFL spotlights on each side (total of 4 bulbs). A 3 inch wide screen is too narrow to catch all the light.

You need very high photosynthesis power on your scrubber to overpower the algae in the display. After you have beaten the algae in the display, you can cut back on the hours of the scrubber if you want.

[steve]

Thanks SM.

I'll go with 4" wide and 12" length.

I'll sort something out with the lights asap. Given the narrow light area, what is the minimum distance I can position the lights away from the scrubber? I'm considering using 1 CFL each side for now and see how this goes as I've reduced feeding.

Knocking the display lights out for a few days shouls be enough to give me the edge once the scrubber is established.

[SantaMonica]

At the least I'd put one 43 watt utility on each side, although 2 spotlights on each side would be better. You can probably get as close as 3 inches.

http://www.algaescrubber.net/CFLtypes.jpg

[steve]

Ok, its been a few weeks since I've posted as I've been actively reading and amending my scrubber over this time. I'm now on scrubber build 3 as of this weekend. Prior to this I was on version 2 which was 4" wide x 12" drop with 2 x 45w spiral CFL (1 each side) with approx 12" x 12" wing reflectors.

I was getting brown/red oily algae on this smaller screen so believe my view on what I'm feeding is more than I think! plus I know there is probably an excess of nutrients in the system given the state of my display.

So what have I done. Weel in addition to the scrubber, I've also added a further 10kg or LR which I thimnk now takes me to 65kg in a system of about 550 litres.

Version 3 scrubber is 10" wide and 12" drop (doesn't seem to be any reason to reduce the length at this stage given I've got the room). I've got a newjet 3000 which is providing flow (measured) at around 1600lph. I still have the same lighting set, but due to increased flow, am getting a lot of spray.

I have built 2 clear plastic screens sitting next to the scrubber screen which is appears to be constantly covered in water. Question: will this water impact the quality of the 2700k light getting through to any degree I should be worried about? I've not been successful to date on understanding or building a saran wrap, so if anyone has any instructions for dummies, please post them!

Will get some pics of the new scrubber over the next couple of days but would encourage feedback on 1) clear screens and the quality of light, 2) saran wrap, and also 3) any evidence to suggest an increased flow (above 60lph) is beneficial?

Thanks!

Steve.

[MorganAtlanta]

Saranwrap-- that's just the most popular US brand name of that plastic film you use to put over food leftovers in the refrigerator. Really any thin plastic film will work. A piece of black plastic garbage bag will work, and will block the light as well and will keep algae from growing up into your slot. That's what I use.

Just cut a piece of garbage bag about 5" x 10". Lay it length-wise along the top of your pipe so that it drapes evenly down each side. It should cover the first inch or so of screen. The pull from the water will keep it down tight and it will stop the spray.

[steve]

Thanks for that. Just for info, in the UK we generally called it clingfilm!

How does the algae grow then if the saranwrap is between the algae screen and the water...or are we saying its as small as it can be just to cover the slot?

[mess7777]

Thanks for that. Just for info, in the UK we generally called it clingfilm!

How does the algae grow then if the saranwrap is between the algae screen and the water...or are we saying its as small as it can be just to cover the slot?

Once you try it out you will understand. The water flows easily between the plastic and the screen. The plastic wrap just keeps it nice and even while stopping any splashing. It won't cause any problems with growing algae.

[steve]

Here we go, pictures of the new scrubber. The lamps are 3" from the screen:- they won't go back any further due to size of sump/reflector but hopefully they will be ok.

You should see plastic wrap keeping most of the splashing at bay...genius idea!

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2053

[steve]

Ok, below pictures shows growth at 14 days and just before first clean. It was starting to grow small strands of hair algae early on but in the past couple of days it started to go dark.

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Thoughts on whether leave as is for now or make any changes?

[Garf]

Mines a new screen also and I clean mine after 7 days. Seems that the more often you clean (within reason), the better the algae grows back.

[mess7777]

looks pretty normal for a first cleaning.

[steve]

3 weeks in and cleaning the screen about every 3-4 days as I keep getting red stuff. There is a little bit of green hair, but I mean a little. Should I keep on with this for a few more weeks or upgrade lighting (little reluctant given cost of nearly 20 GBP each).

Am using 2 x 45W cfl with reflector on an oversized screen of 12" and 12" and flow of 60lph per 1cm

[SantaMonica]

Not enough light. You are losing half the light to the sides. And with 144 square inches of screen, and only 86 total watts to start with, it's easy to see why the screen is staying dark.

Try to get reflectors on the sides.

And cut the screen vertically so it's only 8" wide, and tape off the rest.

[Floyd R Turbo]

He does have reflectors. Just not enough light for the screen area.

How much is feeding?

[steve]

I have wing reflectors behind each cfl, and one at the side (not pictured).

I'm having difficulty working out feed vs siing guidelines.

Generally I feed a large pich of flake in the morning (20mm length, 3mm thick)
In the evening worst case is 1 defrosted frozen cube of mysis + 1 small prawn + 1/4 mussell + sea veggies dried seaweed (40mm x 40mm)

If I reduce the effective size of the screen down by "taping off", any view on what tape is reef save and also won't fall off with water?

I can replace the cfl (currently 2 x 45w) with either 65w, 85w, 105w or 125w.

Should I increase lighting (if so, which size) until display tank loses all the hair algae and then down size?

[MorganAtlanta]

Hmmm.... When you say "45W", is that the actual power used or what the package says as "equivalent Watts"? You want to use the actual watts of the lights in your calculations, not the "equivalent". So a 23 Watt CFL (actual Watts) might say on the package "Equivalent to 65 watts".

[steve]

Yes, I understand the logic and I do mean 2 x 45w of actual power, NOT equivalanet.

So I know its likely I need more power, but how much more? These things are relatively expensive so I don't want to get 2 x 125w and find out they're burning. Equally I don;t want to get 2 x 85w and realise they're still not strong enough....

Views?

[kotlec]

Newer knew they make that powerfull CFL's. What spectrum they are ? Do you know?
We need warm whites with maximum possible red spectrum for srubber.

[MorganAtlanta]

A 12 x 12 is huge by modern standards, so be sure you need that much screen for how much you feed. That would be 12 cubes a day. I'd be inclined to trim the screen down to 6-8" wide and wrap the reflectors around so that most all the light is getting focused on the screen. Cutting the screen in half and focusing the light would have the same effect as doubling the wattage. You could try the plumbers silicon thread tape to wrap the pipe and close down the slot. It doesn't have adhesive, but would hold if you wrap it around several times.

[MorganAtlanta]

I would be interested to see 125w CFL once. Do you have any picture or link to it ? Has to be industrial or military or UFO ...

http://www.1000bulbs.com/product/8374/FC150-35862.html

Like 6 24" T5HO folded in half.

[steve]

125w description appears it to be the same size as the 65w. This is the 2700k version:

http://www.green-lamp.co.uk/shop/article_106/125W-Red-Spectrum-(2700k)-grow-bulb-E27-(625W-incandescent-equivalent).html?shop_param=cid%3D24%26aid%3D106%2 6

The main issue I have with the sizing guidelines is that if you feed anything else other than "cubes" then there's no certainity about required size, is there? I feed a varied diet to my fish so really struggle to understand what size I need.

I originally used a 4" wide by 12" long screen and had the same results as I'm seeing now so am a bit lost!

I'm not sure what you're using for reflectors but proper plant growing reflectors seems to be fixed in shape. I've trimmed it to fit in the sump but its not flexible.

[Floyd R Turbo]

That lamp is nuts man.

I think one thing with the 45W CFL is that with it being so close, the intensity might be too high to run is 18/6. If you're going to stick with a 12x12 screen, you're going to have a little bit of a difficult time lighting it evenly with only one lamp. Switching to 2 lamps of a slightly lower wattage might help.

I think based on your feeding schedule that you posted, you're probably more in line for 6 cubes/day. So I think the problem is two-fold, the light is too close/intense and your screen is oversized.

If you trimmed the screen down to 6" or maybe 8" wide and then tried to back off the lamps to about 1/2" from the reflector, and wrapped it to fit the screen, you would probably get better results. Also you would probably be able to cut down the light hours. I would say 14 on max, but until you start getting green growth, I wouldn't mess with that [i[too[/i] much. What you want is green but if you get yellow rubbery growth, then start knocking the photoperiod down 1 hour per week until you get a consistent green growth. If you get brown slime on top of green, then you're really close, just a bit too much light still. At least that the trend I am starting to notice.

[steve]

Update:

The scrubber did well and brought nitrates down to 5-10ppm and there was virtually no trace of hair algae although I never got the green hair algae to grow on the screen.

Then, in pursuit of perfection and in response to adding a new fis I did the following around 6th July:

Downgraded the screen from 12 x 12 to 8 x 12 as suggested
Lights were 3 months old so replaced them like for like at 2 x 45w 2700k cfl
Introduced copperband butterfly and increased food to tank (on top of what I was feeding already) between 0.5 to 1 cube per day to try and entice him to eat

During this time the nitrates have increased to 25ppm. So this weekend (19th august) I did the following:

Added 2 x 20w cfl to each side (ie 4 bulbs). The colour looks the same as the 45w 2700k but I'm not 100% sure. These are about 2"-3" from the screen
Reduced lighting time down to 9 hours as I'm now at 85w each side
Increased flow rate to just about the recommended 60lph per cm of screen width

I've added pictures to show the current state of the screen. Problem is tht when I did the changes at the weekend I did not need to clean the screen, so didn't. So what you see is the result of 2 days of growth based on new parameters. Is this a waiting game or do you suggest anything else. I'm actually a bit panicy as my copperband still isnt feeding and nitrates continue to increase!

[Floyd R Turbo]

1) what else is growing in the sump? Looks like marine plants and a later of chunks of algae

2) Is that a single reflector behind those 2 lamps?

3) in the third pic, are the lamps moved to take the pic, or is that how they are always positioned?

[steve]

1) its chaeto and caulerpa - I've just thinned these out after taking the photo (probably by one third).
2) there are 2 reflectors, one behind each bank of 3 light bulbs.
3) The 2 lamps aren't moved (I didn;t want them to close to burn the screen), however what is removed is the 45w cfl which sits in the middle and also the reflector which this is mounted on. I then put a piece of reflective carbaord along the side to reflect lost light coming out of the side. Once these are positioned there is very little seepage.

The second photo gives you an ieda of what it looks like with just the end reflector missing but with all bulbs and main reflectors in position.

I've also just removed the acrivated carbon and rowaphos!

[mess7777]

Your copperband can handle the nitrates, fish generally aren't affected by lowish nitrates. This is more of a concern for corals. That said, I have read a lot about copperbands being finicky eaters and a lot of people not having great success.

[steve]

Your copperband can handle the nitrates, fish generally aren't affected by lowish nitrates. This is more of a concern for corals. That said, I have read a lot about copperbands being finicky eaters and a lot of people not having great success.

I'm not sure the reasonably high level is helping to stimulate him to feed, but agreed its the corals and shrimps I'm more worried about, especially since these have only been in about 6 weeks after previously had to remove them due to the rocks being fully carpeted with hair algae. Its just a shame that we're not allowed to have the californian blackworms in the UK as this is almost certain to get him feeding according to a number of American reef sites.

[Floyd R Turbo]

I don't know if copperbands are sensitive to N but most fish can tolerate the levels you are at rather easily.

As for your setup, the rowaphos was likely pulling down P, and if it was at zero, this might inhibit growth and N uptake. it is a likely culprit. Your chaeto and caulerpa are competing as well.

Your lamps are strong, but not individually reflected, and your reflector needs to be moved closer to the lamp and screen. Same bend radius, just make it come as close as it can to the lamp and then the ends of it should almost touch the screen. With it that far away, you're losing a lot of light, and the bend of the reflector cannot match the light profile or it will reflect the light back onto the lamp. you want a parabolic reflector close to the source. hard to describe in words.

[Floyd R Turbo]

3125

Ok quick paint sketch showing this. Doesn't include the 2 additional lamps which I don't think you need if you do this and remove the other macros.

Left pic is what you have

Right pic is what you want

[SantaMonica]

Macro's need to go.

[steve]

Macro's need to go.

Ok! I may need to do this over a week or 2 as I don't know much nitrate these are already pulling out and hence don't want a sudden spike.

Give the recent changes I made, when would you expect to start to see green, before I start playing with set-up again?

Floyd - not sure I understand the drawing. There is about 2" from lamps to screen and the lamps to the reflctors is between 3" and 5" depending on bulb/reflector position. Given I'm using 3 bulbs on each side, won't one reflecor give more light spread and limit the chance of burning rather than focussing the light on a specifi carea of the screen?

[Floyd R Turbo]

1) Your reflector needs to be close to the lamp such that if you look across the (vertical) edges of the reflector, the lamp is "hidden".

2) the curvature of your reflector cannot match the curvature of your lamp. Think of concentric circles. Look at the left side of the drawing. The reflector is shaped (in that drawing) such that it is a portion of a circle that matches the "arc" of the circle created by the lamp profile (looking down). This means that light coming from the lamp will be reflected directly back into the lamp (at least, a significant portion of it). You do not want this.

So in the second (right half) picture, the lamp is very close to the reflector such that light originating from the lamp cannot be reflected back into it due to the angle of incidence on the reflector. It is instead reflected forward to the screen. Remember you do not have to move the lamp in this situation, at all. Just move the reflector closer to the lamp and screen, that's all. You will increase light directed at the screen by I estimate 25-30%.

I am a EE working in consulting and have done a fair amount of lighting design and attended many (architectural) lighting seminars. Trust me on this. There is an entire sector of that industry devoted to maximizing output of a light source via reflector properties.

Also I would regularly wipe off the reflector, and is it actually touching the water surface? That is big bad no no if it is.

[SantaMonica]

Pull one, wait a week, then the others.