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Andy_cy
05-20-2013, 08:55 PM
Hi guys, I'm from singapore and over here, freshwater aquariums are much more common than SW ones.

Recently setup my own diy ATS for my 200L tank, it's working very well, having green hair algae growing from day 2 onwards. Just did my first official screen cleaning today, after about 14 days from setup.

I realise that FW ATS doesn't really get very thick, as the strands of GHA just grows longer towards the end of the screen, and may sometimes fall off. My screen is extremely rough, after roughing it twice on both sides, it holds on to the strands of GHA pretty well.

Does anyone know specifically what nutrients does GHA absorb readily? Apart from nitrates and phosphates, is ammonia taken in too? I have been wondering, if the ATS can readily remove ammonia, would it be endangering the beneficial bacteria in my bio filter? Then again, due to the 14-hour light cycle I provide my ATS with, I know my bio filter will have 10 hours of ammonia to itself. So at most, the beneficial bacteria will be starved or competing for 14 hours when the lights come on, isn't it? Big question is, will this harm the bio filter by anyway?

If the bacteria colony shrinks due to the introduction of an ATS, then right after a full cleaning, the shrunken colony of bacteria will not be able to handle the bioload, thus causing traces of ammonia and nitrite for a few days until the algae starts to grow again, right? Isn't that dangerous? Having the livestock exposed to toxic nutrients for 1-2 days every week after you do a cleaning..

Hopefully someone who has experience with FW ATS can help me with those questions. I will post pictures of my ATS soon when I get home.

Currently the main reason for using an ATS is to help reduce my nitrates, hopefully to an undetectable level. Because the rate at which nitrates are produced in my tank is clearly much higher than my weekly water changes can remove it. It resulted in a nitrate level of about 150-200 mg/L. After a week of daily water change, I ended up with about 50mg/L nitrates. Right now, nitrates are reaching 100mg/L again, even though algae is growing like mad in my ATS. I'm just crossing my fingers and hoping that this week's growth can bring the nitrates down a good amount.

All inputs are greatly appreciated :)

SantaMonica
05-21-2013, 02:49 AM
Welcome,

Yes ammonia is absorbed, primarily. It won't alter your bio filter because the ammonia hits the bio filter before the ammonia ever gets to the scrubber. Also, scrubbers add carbon (glucose, etc) to the water which feeds the bacteria even more, making the bacteria even more able to eat ammonia, nitrate, etc.

Andy_cy
05-21-2013, 05:47 AM
Welcome,

Yes ammonia is absorbed, primarily. It won't alter your bio filter because the ammonia hits the bio filter before the ammonia ever gets to the scrubber. Also, scrubbers add carbon (glucose, etc) to the water which feeds the bacteria even more, making the bacteria even more able to eat ammonia, nitrate, etc.

Thanks boss.

My tank has 2 pumps, one pumping water into my wet/dry filter, the other pumping water to my ATS. So in my case, ammonia in the water will be supplied to both filters simultaneously, no?

Well, what you said is a great relief to me, knowing that the algae actually boosts nitrifying activities is awesome. Hopefully my ATS can handle the amount of nitrates my fishes are producing.

Other freshwater ATS users please join this discussion and share more experiences!

Floyd R Turbo
05-21-2013, 05:49 AM
There is evidence to support the concept that a scrubber has more of a symbiotic relationship with the bacterial colony, rather than a competitive relationship. So I would not worry about the bacterial colony shrinking.

Depending on how large your scrubber is, the nitrates should start to stay lower on a more steady basis.

Walleyefisher is a good person to ask about the specifics of freshwater scrubbers - he has 3 of mine running

Andy_cy
05-21-2013, 06:04 AM
There is evidence to support the concept that a scrubber has more of a symbiotic relationship with the bacterial colony, rather than a competitive relationship. So I would not worry about the bacterial colony shrinking.

Depending on how large your scrubber is, the nitrates should start to stay lower on a more steady basis.

Walleyefisher is a good person to ask about the specifics of freshwater scrubbers - he has 3 of mine running

Thanks Floyd.

It seems that the efficiency of a freshwater scrubber is much more limited than a saltwater one. From my observation, a single flat screen can only hold that much hair algae.. Any more and they start falling off. And I don't think it's an issue with my screen's roughness as I am pretty sure my screen is rough as hell! I roughed it so much that some parts of the mesh broke off haha. I'm thinking whether stacking 2 screens on top of each other would help. This way, more anchor points are available for the hair algae to cling onto. Any suggestions?

Floyd R Turbo
05-21-2013, 07:50 AM
I think it may have to do with saltwater and calcification. Not 100% sure, but it does make sense - saltwater will form a calcified layer on the screen to which the algae can anchor to. Also I believe that FW algae does grow long and more fine and hair-like, and when it gets longer, it would therefore have more tendency to pull off. Basically, you need to clean more often with FW.

Andy_cy
05-27-2013, 09:03 AM
Hi guys, I was hoping more of you who are using FW ATS can post your screens or setups to share with the rest here.
Anyway, here's mine. Just took the pictures in the dark at night, so its not very clear.

This is my screen at day 5 of the 7-day cleaning cycle. Day 5 after its first cleaning. Due to be cleaned in 2 days time.
Quite a lot of green growth, but its fine strands of green hair and it doesn't thicken in width.
http://farm8.staticflickr.com/7317/8855103893_4ac83499db_z.jpg

This is my setup. Its a custom built glass tank with two pockets for the lights and has two holes drilled on one of the walls
to drain water back into main tank. Each light set has just one 20W LED (warm white) with a big reflector. Its sold as an
outdoor LED floodlight, which is rain-proof.
http://farm6.staticflickr.com/5329/8855718188_44e4e30128_z.jpg

Although the algae seem to be growing well, its been almost 2 weeks but I haven't seen a significant decline in my nitrates.
How long does it usually take to bring down nitrates to be almost untraceable? Will my screen get any thicker, or is it fully
saturated with hair algae already? Because what I notice is that algae will eventually fall off from the screen, meaning that
there isn't enough space for new strands to cling on? I also intend to DIY 2 sets of LED fixtures to replace the existing one.
Gonna use the 660nm + 455nm setup for maximum growth. But that's not gonna be too soon.

Hope to see more FW ATS builds and pictures. I just wanna learn more about it :)

SantaMonica
05-27-2013, 11:22 AM
FW is much thinner than SW. Without support, the long strands will fall off. Your growth is good though, so it is on the way.

Depending on your nitrate, each screen cleaning could lower it 5 or 10 points.

Floyd R Turbo
05-27-2013, 01:46 PM
Try Garf's trick of putting tiny zip ties on the screen. This might give a little support to the growth.

Andy_cy
06-07-2013, 06:51 PM
Another week passed but still no signs of lowered nitrate levels :(
Nitrates at ~25mg/L right after my weekly water change, and tested again before the following week's water change, it raised to ~50-70mg/L.
Experiencing tremendous algal growth, but the test results state otherwise. Is there anything I'm missing out here?
Btw, my 200L tank has one 12" arowana and four 4" datnoides, feeding about 8-10 super worms and 6-8 food sticks daily.
It's just a grow out tank, they will be transferred to an 800L tank later this year.

Floyd R Turbo
06-07-2013, 08:45 PM
That is a rather heavy load. You're still only a month in on the scrubber, I would give it time. Are your nitrate levels rising slower than they were before you added the scrubber?

SantaMonica
06-07-2013, 09:35 PM
The FW algae might be consuming more ammonia than nitrate. If ammonia is available, nitrate is not needed.

Andy_cy
06-08-2013, 06:37 AM
@Floyd
Well, yeah it does seem to slow down the rate of nitrate build up. But the screen seems to be already at it's maximum efficiency because any new algae growth causes existing ones to fall. My filter sock is cleaned daily because so much algae falls off every day. Haven't tried Garf's zip tie method yet cos I tried searching but don't see it. You reckon I need a dual screen?

@SantaMonica
Is that right? I tested my ammonia level too, it's flat zero for sure. Since ammonia is limited, should I be looking into phosphates and potassium? I dose a cap of seachem phosphates after each water change just in case. But have never doesd potassium. The algae seem to be growing well, not like there's any obvious signs of macro nutrient deficiency. Any other suggestions?

Thanks for all the help, you guys are wonderful!

Floyd R Turbo
06-08-2013, 06:39 AM
No dual screens.

look for Garf's thread "S.S.S.S." basically though you just find the tiniest zip ties you can (3" usually) and secure them to the screen. I haven't tried it on a vertical screen yet

SantaMonica
06-08-2013, 09:57 AM
When the fish pee, the ammonia goes straight to the scrubber before it can be fully consumed by the bacteria on the hard surfaces. So the reason the ammonia is zero might be because the scrubber is growing so much.

Two things to test would be doubling the light wattage, and or/adding another scrubber. At some point of additional scrubber growth, the nutrients have to come from the nitrate.

Andy_cy
06-08-2013, 09:33 PM
No dual screens.

look for Garf's thread "S.S.S.S." basically though you just find the tiniest zip ties you can (3" usually) and secure them to the screen. I haven't tried it on a vertical screen yet

Ok, I've seen that. But I'm not sure how much it will help on a vertical waterfall screen. I have an idea, will post an update once it's complete. Thanks for the suggestion.


When the fish pee, the ammonia goes straight to the scrubber before it can be fully consumed by the bacteria on the hard surfaces. So the reason the ammonia is zero might be because the scrubber is growing so much.

Two things to test would be doubling the light wattage, and or/adding another scrubber. At some point of additional scrubber growth, the nutrients have to come from the nitrate.

My tank currently has 2 pumps, one for the scrubber and one for my filter. The one for the filter is slightly stronger too. Since both pumps work simultaneously, once ammonia is released, both the scrubber and filter should get some of it right? Furthermore, the increasing level of nitrates simply suggests that my filter has been getting quite a good amount of ammonia right? I'm pretty sure the scrubber doesn't use up all the available ammonia, the bacteria probably gets a good amount of it too.

Only mystery is why isn't my nitrate level dropping even when the screen is growing great amounts of algae? My only conclusion now is that this 'great' amount of growth is still not enough to keep up with the nitrate production rate. I might need another screen but I really hope not. I'll give it another month to see how it goes. Will do an update later on this week.

SantaMonica
06-09-2013, 02:46 AM
Well at the least, increase light hours as much as possible.

Andy_cy
06-09-2013, 08:04 AM
It's currently set at 19hours per day. The max I can push it to is 20?
Maybe the warm white LED lights I'm using is too inefficient. It's hard to get the DIY led parts here in sg. The star led chips they sell here are just labelled by colour, red/blue/green etc. none of them knows what 660nm is. It's pretty funny lol. They make me feel like an alien when I ask for it..
My intention is to just build a diy red led set for this scrubber. Even though it's not 660nm, it should at least be 600nm or thereabout. Way more efficient than warm white I guess. Oh well, update when I make changes. For now, just wait and see.

Floyd R Turbo
06-09-2013, 08:05 AM
PM walleyefisher. He has 3 of my scrubbers all on FW tanks. He would be able to give you more insight.

Andy_cy
06-12-2013, 05:52 PM
http://farm8.staticflickr.com/7413/9030199180_61faeaee82_z.jpg

The amount of algae I collected on 1 side of the screen. This is excluding the amount that falls off daily.
So I tested my nitrates again... On tuesday after water change, it was 25mg/L. Today, it reads 70-80mg/L.
The results really disappoint me and I feel like trashing the whole setup..
I'll give it another month, hopefully something miraculous happens. Cheers

Floyd R Turbo
06-12-2013, 07:05 PM
Let's get the stats on your system. Answer the following:

What are the dims of your screen, Length and Width?

How many GPH are you pumping across it? Is the answer the actual measured flow, or calculated based on a pump head loss chart?

How many hours/day are you lighting the screen? Single photoperiod, or do you split it up throughout the day?

How many days do you let the screen grow between cleaning?

Now about your tank:

BEFORE you added the scrubber, this is what you said was happening:




So let me see if I have this correct: After PWC, 50 ppm (mg/L). One week later, 150-200 ppm. That's a 100ppm increase in one week, or possibly as much as 150ppm increase

AFTER scrubber, you have having this:

[quote]Nitrates at ~25mg/L right after my weekly water change, and tested again before the following week's water change, it raised to ~50-70mg/L.

On tuesday after water change, it was 25mg/L. Today, it reads 70-80mg/L

So if I am understanding this right, you have roughly a 50 ppm increase in one week

That's assuming the same % of PWC each week.

I get your frustration, you want it not to rise at all. But you have to look at the positive side of this - your tank is much healthier going from 25-75ppm instead of 50-150 (or 200).

But before I jump to a conclusion, answer the questions in the first part of the post, and then correct me if I wrong in any of my assumptions or interpretations of your posts

SantaMonica
06-12-2013, 08:26 PM
I dose a cap of seachem phosphates after each water change

Don't do this. You do not need to dose anything to get better filtering.

Andy_cy
06-12-2013, 09:05 PM
Hi Floyd, thanks for going through this with me.

Screen dimensions: 29cm(L) x 21cm(B)
Pump: Rio 6HF (350GPH@1ft). ATS is 2ft above, so flow rate should be ~280gph?
Lighting: 20w warm white led floodlight, one on each side. Small diffuser in front of led bulb to prevent my screen from forming a bald spot in the middle. My light looks exactly like this http://www.ebay.com/itm/190725107032
Light is about 4" away from screen, behind a 6mm glass panel.
Photoperiod: single photoperiod of 19 hours daily.
Cleaning regime: +/-5 days per side alternatively. I will usually wait till the growth is too thick for the algae roots to hold on before cleaning. By then, the screen is usually growing 3D but not as thick as the SW ones I've seen. Also, as the screen grows, loose algae falls off often, my filter sock collects about a 1" sphere worth of algae daily.

Tank history:
- ~200L run on a wet/dry filter
- Before adding the ATS, nitrates were at ~200mg/L with weekly water change.
- 1 week before ATS, did daily water change and got a ~50mg/L reading.
- Introduced the ATS, did more nitrate tests, tested once every 2 days.
- Towards the end of my water change cycle, reading always show 70-100mg/L. After water change, it's always ~30mg/L.

Live stock:
- 1 x 12" Asian arowana
- 4 x 4" indo tigers

Daily feedings:
- 8-10pcs super worms OR 2 whole market prawns
- 5-6pcs Hikari food sticks

Did I miss out any other info? Currently, I'm planning to change my lights to a diy LED set using 660 and 455 bulbs. Only problem is that my country doesn't supply these parts readily. Shipping over is kinda expensive. Still a ? to me for now. And yes, it's frustrating when I see that awesome 3D growth on my screen but that vial of dark red liquid from my nitrate test result just sits there and give me an evil grin. Damn.. Lol

Andy_cy
06-12-2013, 09:08 PM
Hi SM, alright I will stop dosing any excess nutrients from now on. Reason why I did that was to balance the NPK hoping to rule out any deficiencies. I guess this is algae I'm dealing with, not plants haha.

Floyd R Turbo
06-12-2013, 09:15 PM
Hi SM, alright I will stop dosing any excess nutrients from now on. Reason why I did that was to balance the NPK hoping to rule out any deficiencies. I guess this is algae I'm dealing with, not plants haha.

No you are right in your line of thinking, but unless you actually have a deficiency in P or K, dosing them would not help. Do you test for P or K, and if so, what kits and what are your readings?

Andy_cy
06-12-2013, 09:17 PM
I am also in the midst of designing an ATS for my 800L tank, live stock is more, feeding is way more. I'm planning to use a double screen, water will be fed by diy overflow pipe. But all of this will not happen if this current scrubber I have is not showing positive results. Because it's gonna cost a lot more for this unit. Hoping to perfect this as soon as possible so I can move on to curing my 800L tank's nitrate problems.

Andy_cy
06-12-2013, 09:21 PM
No you are right in your line of thinking, but unless you actually have a deficiency in P or K, dosing them would not help. Do you test for P or K, and if so, what kits and what are your readings?

I don't test for P and K because in freshwater, these nutrients are not critical. Didn't wanna spend the extra money for these kits. Do I need to know the P and K levels in order for my scrubber to be a success? Algae seems to be growing fine at this point.

Floyd R Turbo
06-12-2013, 09:31 PM
Hi Floyd, thanks for going through this with me.

Screen dimensions: 29cm(L) x 21cm(B)

Converting this to inches is about 11.5 x 8.25, I'm guessing from your pics that the 8.25 is the width?

You will want a minimum of 8.25 x 35 = 290 GPH, measured. I would go much higher, like 50 GPH, or 400 GPH. If the screen is 11.5" wide, then your problem is bigger.


Pump: Rio 6HF (350GPH@1ft). ATS is 2ft above, so flow rate should be ~280gph?

I guarantee you are not getting this much flow. I run a Rio 6HF on one of my L2s at less than 12" vertical head and I measure 240-260 GPH right after cleaning. At the 2 week point, if I haven't taken the screen out of the slot pipe and scrubbed the top edge (which I typically don't on the particular tank it is on) then it's easily 160 GPH. With 24" of head (and the slot pipe adds about 24" of head also) you're probably way under flow. If you have the capability to measure this, you might want to check that out to verify, but that's my bet.


Lighting: 20w warm white led floodlight, one on each side. Small diffuser in front of led bulb to prevent my screen from forming a bald spot in the middle. My light looks exactly like this http://www.ebay.com/itm/190725107032
Light is about 4" away from screen, behind a 6mm glass panel.

Have you had the bald spot issue before? Now that you are getting decent growth, it should not be as much of a factor. Take the diffuser off.


Photoperiod: single photoperiod of 19 hours daily.

Split it up into 3 photoperiods of 7 hours each, with 1 hour in between, if your timer allows this. Or, you can do 6 photoperiods with 30 minutes in between each.


Cleaning regime: +/-5 days per side alternatively. I will usually wait till the growth is too thick for the algae roots to hold on before cleaning. By then, the screen is usually growing 3D but not as thick as the SW ones I've seen. Also, as the screen grows, loose algae falls off often, my filter sock collects about a 1" sphere worth of algae daily.

Sounds about right.


Tank history:
- ~200L run on a wet/dry filter
- Before adding the ATS, nitrates were at ~200mg/L with weekly water change.
- 1 week before ATS, did daily water change and got a ~50mg/L reading.
- Introduced the ATS, did more nitrate tests, tested once every 2 days.
- Towards the end of my water change cycle, reading always show 70-100mg/L. After water change, it's always ~30mg/L.

So that's about 50 gallons (standard 55g tank maybe?)

From what it sounds like, the scrubber has reduced the rate of increase of your nitrates - correct?


Live stock:
- 1 x 12" Asian arowana
- 4 x 4" indo tigers

Daily feedings:
- 8-10pcs super worms OR 2 whole market prawns
- 5-6pcs Hikari food sticks

Did I miss out any other info? Currently, I'm planning to change my lights to a diy LED set using 660 and 455 bulbs. Only problem is that my country doesn't supply these parts readily. Shipping over is kinda expensive. Still a ? to me for now. And yes, it's frustrating when I see that awesome 3D growth on my screen but that vial of dark red liquid from my nitrate test result just sits there and give me an evil grin. Damn.. Lol

Sounds like you are using the API test kit for nitrate, correct? Here's a hint, to get a true reading, you need to dilute the sample and test, then multiply the reading. Lower range is more accurate. Past about the 40 ppm reading, it's useless IMO. Dilute your tank water with distilled or RODI water. Use 4 parts RODI to 1 part tank water, the multiply your reading by 5. If still >40, dilute 9 parts RODI to 1 part tank water, test. Etc.

You can get the same fixture in 10, 20, 50w, etc with 660 red online also.

EDIT: oh yeah...that's a ton of food man. Do you run anything else besides the scrubber??

Floyd R Turbo
06-12-2013, 09:35 PM
I am also in the midst of designing an ATS for my 800L tank, live stock is more, feeding is way more. I'm planning to use a double screen, water will be fed by diy overflow pipe. But all of this will not happen if this current scrubber I have is not showing positive results. Because it's gonna cost a lot more for this unit. Hoping to perfect this as soon as possible so I can move on to curing my 800L tank's nitrate problems.

Always good to try it out on a smaller, less expensive setup first and learn what works and what doesn't....


I don't test for P and K because in freshwater, these nutrients are not critical. Didn't wanna spend the extra money for these kits. Do I need to know the P and K levels in order for my scrubber to be a success? Algae seems to be growing fine at this point.

I would say it is inconclusive whether or not these are a factor at this point. You are growing algae well. I think you are getting plenty of nutrients from the food you feed.

Andy_cy
06-12-2013, 10:04 PM
Yes 8.25" is my width. Haven't really measured the exact flowrate I'm getting out of that rio pump. Might do it tomorrow if I'm free.

I had the bald spot issue at the very beginning, week 1. So I solved it immediately and had even growth till now. I'll try without the diffuser on one side to give it a test.

Yes, my current timer will allow the 7+1 cycle. I'll change it tonight when I get home. That means 21 hours of light, 3 hours rest per day. Phew.. The algae's gonna complain. :) I might upgrade to a digital timer, then I'll try the 3.5+0.5 cycle.

Well, my tank is 4ftx2ft with 1.5ft height. Filled to a level which is about 200L. Yeah I believe the scrubber helped reduce the speed of nitrates build up.

I'm using Sera test kits now. Haven't tried the API test kits, Sera seems to be working fine. Sera test kits measure up to 100mg/L for nitrates. Only when I get a reading of 100, then I will do a second test with 50% dilution, which doubles the range. I'll try testing today by diluting to obtain a more accurate reading.

No intention of getting this light set anymore. I spent sgd$100 for 2 sets of it and it sucks because it heats up so much. I believe it's not producing 100% of light it should, by now. I will diy the deep red and royal blue led set as soon as I find the right parts here.

Yeah feeding a lot now because the arowana is young, once it reaches 15", it will be transferred to my 800L tank. Other than the scrubber, the tank is running on a top filter (wet/dry). It's coping well with the bioload. Always keeping ammonia and nitrite ~0ppm. But coughing out tons of nitrates.. Putting all my hope on the scrubber now as I really don't want to use a denitrator. I like how a scrubber works and all the benefits, but first, it has to bring my nitrates down. Waiting for that I happen haha.

Your help is golden :)

Andy_cy
06-14-2013, 09:17 AM
Tested nitrates today. Reading was somewhere between 30-40mg/L.
Tried the diluting method suggested by Floyd, it didnt detect any nitrates. I diluted 1 part tank water with 3 parts distilled water. Which means any reading from this test should be multiplied by 4 to obtain the actual result. Unfortunately, the solution was pure yellow, indicating zero nitrates. Mystery.. I might get an API or waterlife test kit to counter check.

If the first test of ~40mg/L is true, then it must be a miracle. Because I just did screen cleaning and the screen is so low on algae growth right now. I have also removed the diffuser from the lights. Algae in the middle don't look like they're dying off yet.

If I switch to the photo cycle of 3.5(on)-0.5(off), will the fluctuating pH cause any harm to the fishes?

Floyd R Turbo
06-14-2013, 09:29 AM
Many kits will have only a slight variation in color at low range. For example, API saltwater nitrate 5 and 10 readings are nearly identical. For your kit, I would test the diluted sample and a distilled sample side by side to help visualize what is actually zero. If you dilute what looks like 30-40 and get what looks like zero, you might be misinterpreting your 40 reading to be higher than it is. It took me a while to really peg what color was what with API due to difficulty interpreting the colors in this way.

SantaMonica
06-14-2013, 10:50 AM
pH will not change that much.

Andy_cy
06-14-2013, 06:54 PM
Many kits will have only a slight variation in color at low range. For example, API saltwater nitrate 5 and 10 readings are nearly identical. For your kit, I would test the diluted sample and a distilled sample side by side to help visualize what is actually zero. If you dilute what looks like 30-40 and get what looks like zero, you might be misinterpreting your 40 reading to be higher than it is. It took me a while to really peg what color was what with API due to difficulty interpreting the colors in this way.

Ok, I think I'll get a new nitrate test kit tomorrow and do some tests all over again. Like what you've said, test pure distilled water and compare with diluted sample, sounds good.


pH will not change that much.

I don't know what your "much" refers to but I have a pH meter that provides a live feed of pH value of 0.01 accuracy. Whenever the light comes on, pH rises by 0.2-0.3. Right now my pH sits at 7.51 and when lights go off, it falls to ~7.30.

If I use the 3.5/0.5 light cycle, that means my pH will fluctuate 6 times per day! Up down up down... Is that a problem?

Anyway guys, I'm planning to use a new screen that I've just completed, it's made of Velcro, the hook side. Spent some time designing and building it. It's finally done and I will probably hook it up tomorrow. I wanna know if the 3.5/0.5 cycle is good for a fresh screen or is it better to stick with 20/4 at first until the screen becomes seasoned?

SantaMonica
06-14-2013, 07:02 PM
Those small pH changes should not matter.

Try both light cycles and see which one works better.

Andy_cy
06-14-2013, 07:06 PM
Just to touch on my new Velcro screen, it's made of the hook side of Velcro strips which you can get from craft stores.

I realized that GHA in freshwater lose their attachment to the screen easily, and even though how much I've roughed my canvas screen up, a good amount of GHA still falls off daily.

With all the millions of tiny hooks on my new screen, hopefully the GHA can cling on better. Also, the hooks are ~1-2mm in height, which means that during cleaning, I will scrape off all 3D growth and still have that 1-2mm base layer intact on the screen, hopefully will help kick start the regrowth of algae.

I used a thin clear PVC sheet as base material, and pasted the Velcro strips all over as evenly as possible, on both sides of course. This forms a nice thick mat of million micro hooks. My Velcro strips came with sticky tape on the back side so it's pretty easy. Just hope it doesn't loose it's stickiness over time with constant exposure to water.

not sure if anyone really did this before, but enlighten me if this is a good idea. It's mainly for freshwater only, saltwater algae has very good attachment to the usual screen already.

Floyd R Turbo
06-15-2013, 09:28 AM
Many types of screen material have been tried. It all comes back to the plastic canvas. Velcro attached to PVC is now one sided which means less water flow through from each side to the other side, and no light penetration between the sides. Any adhesives will leech into the water and really should be avoided, FW or SW, IMO. I would just stick with canvas.

Andy_cy
06-15-2013, 10:49 PM
Many types of screen material have been tried. It all comes back to the plastic canvas. Velcro attached to PVC is now one sided which means less water flow through from each side to the other side, and no light penetration between the sides. Any adhesives will leech into the water and really should be avoided, FW or SW, IMO. I would just stick with canvas.

1) Velcro is pasted on both side of the thin PVC sheet.
2) I have lights shining on both sides.
Have read your other posts regarding a Velcro screen as well. You mentioned the holes of a plastic canvas is important for regrowth after a screen cleaning. Since the Velcro hooks retains a good amount of algae after scraping, isn't that more beneficial than empty holes that allow light shining through?
3) I have no idea what chemicals will leech into the tank, at this point, this is the only thing I'm worried about. Anyone has any idea if adhesives are harmful to fish?

Anyway, the reason why I'm gonna try this Velcro screen is because I realized that regular canvas screens are not the best at holding on to freshwater GHA. Definitely agree that it's perfect for SW, no doubt about that. I will start another thread regarding this Velcro thing.

ANYWAYS... Just to update on my ATS, I got the digital timer and I'm running the 7/1 photo cycle now. Also took your advice on removing the little diffuser for my lights, it seems the screen is coping well, no bald spots. Will do another nitrate test tomorrow.

Andy_cy
06-19-2013, 07:42 AM
After switching to the 7-1 photo cycle, my screen just turned dark brown to black now. After about 2 days. Any explanations?

Floyd R Turbo
06-19-2013, 07:52 AM
Could be many things, usually this would indicate high nutrients, but not sure. Is this the velcro screen or the original screen?

Andy_cy
06-19-2013, 08:02 AM
Still on my original screen, I realise that the middle portion is last to turn brown. The sides and corners are totally brown now. Have the algae died? I removed the light diffusers. I'm probably gonna put the light diffusers back on, and give the screen a full cleaning.

My screen has about 100 sq inch, and I'm gonna change my lights tomorrow. By using 2 x 23w cfl on each side, will I get decent growth? 2 bulbs each side, 4 bulbs total. 92w of light in total.

Floyd R Turbo
06-19-2013, 08:27 AM
Well, if you took the diffusers off and growth changed negatively, put the diffusers back on. You really have to look at this as an experiment at this point - you're trying to figure out the issues, so you change one thing and look for differences.

The next thing I would do actually is put only one of the diffusers back on, and leave the other in place, and give it a week

If you are going to change light sources, do the same - change only one side at a time. This way you can see the difference between each side. Not exactly scientific, as there is light bleed through...

2x23W CFL on each side should be good, that will put you at the standard light level.

I just had another thought though. Not sure if this is the correct line of thinking, but if you had a problem with nutrients rising even when you were growing green algae on the screen, then you increased the light by removing the diffusers and ended up with brown and black growth, this might actually indicate that you are now taking up nutrients at a higher rate and this is turning the algae black. What I'm thinking is that you might just leave the screen alone for a while, cleaning it every 3 or 4 days to get rid of the black, and keep an eye on nutrients. I'm wondering if it is actually working better now.

Andy_cy
06-19-2013, 09:17 AM
Yeah I actually put the diffuser back on one side, and after just 1 day, there was a significant difference. The side without diffuser had more black algae. The black algae I have is exactly like the green ones, they are in strands but dark brownish to black.

I just cleaned both sides of screen and planning to use CFLs on both sides tomorrow. By observation, there is a lot of black growth towards the sides of the screen while the middle has more greens, but under the greens lie a layer of black as well. Since the floodlights I'm using uses a 20w chip in the middle, I'm guessing the reason the sides turn black is due to lack of light. So that's why I'm changing to cfl for more even lighting.

I'll test the CFLs for a week, and see if I get a full green mat. I would very likely change to LEDs because CFLs just take up too much energy. I still can't find a store that sells those star led chips here and shipping costs a bomb :(

Thanks again for your help, it's great to get professional advice from you :)

Btw, your new scrubbers look great!

Andy_cy
06-19-2013, 09:20 AM
Just to add, yesterday was water change and nitrates were lowered to 25. Even though it's lowered, the algae still turned black after today. So I think it's probably not due to high nutrients. Lets see if the CFLs will solve the problem.

Floyd R Turbo
06-19-2013, 09:41 AM
My point was more related to the algae possibly turning black because it is adsorbing more nutrients. This is possibly a different way of looking at things. It has always been presented that algae grows black because it is growing in high nutrient water. However your example seems to go against that. You were growing green algae well in high nutrient water, then when you increased the light, that is when it turned black.

Do you see what I'm getting at? My thought here is that it's not that the algae grows black simply because it is in high nutrient water, it is growing black because it is adsorbing more nutrients. Meaning, it's working better. This is why I said to leave it alone and see what happens. The black algae will obviously block light better to the layers beneath, but this is typically a SW thing, where the algae grows thicker. Your algae is still stringy and hair-like, so it shouldn't block light to the base. I would still clean the screen off every 4 days or so just to be sure, but keep an eye on your nutrients and see what happens.

If your nutrients don't rise as fast, then I'm right. Logically, that is what I would expect to happen. But, I'm not sure how much of a difference you will notice, and there still is the possibility that something else has affected the growth on the screen.

SantaMonica
06-19-2013, 10:02 AM
Well nutrients did not change. Apparently it just does not like that photoperiod.

Floyd R Turbo
06-19-2013, 10:33 AM
2 days is not enough time to tell how changing something has affected the overall system.

Andy_cy
06-20-2013, 09:15 AM
My point was more related to the algae possibly turning black because it is adsorbing more nutrients. This is possibly a different way of looking at things. It has always been presented that algae grows black because it is growing in high nutrient water. However your example seems to go against that. You were growing green algae well in high nutrient water, then when you increased the light, that is when it turned black.

Do you see what I'm getting at? My thought here is that it's not that the algae grows black simply because it is in high nutrient water, it is growing black because it is adsorbing more nutrients. Meaning, it's working better. This is why I said to leave it alone and see what happens. The black algae will obviously block light better to the layers beneath, but this is typically a SW thing, where the algae grows thicker. Your algae is still stringy and hair-like, so it shouldn't block light to the base. I would still clean the screen off every 4 days or so just to be sure, but keep an eye on your nutrients and see what happens.

If your nutrients don't rise as fast, then I'm right. Logically, that is what I would expect to happen. But, I'm not sure how much of a difference you will notice, and there still is the possibility that something else has affected the growth on the screen.

Yes, I get what you mean. Because of the rising nutrients, and without the diffuser, the black algae takes over as the conditions are favouring it.

Well, in the past, I had nitrates as high as almost 100mg/L but the screen still grows green hair and it gets thick and starts falling off.
After my water change, nitrates at ~25mg/L and the algae turned black 1 day after, even when nutrients are at its low.

So compared to the past, nothing changed except for removal of diffuser and photocycle (7-1). My conclusion is that it could be due to the increased light from that 20W LED chip causing the GHA to die and turn brown/black OR could be due to the new photocycle that the algae didn't like. But since the photocycle has been tested and proved working, I'm gonna say its the light that's causing death.

Well, thats the past. CFLs are installed now. They produce SOOOO much heat. Its crazy. I really need to get a DIY LED panel soon.


2 days is not enough time to tell how changing something has affected the overall system.

You're probably right, you have also done way more tests than I did at this scrubber thing. It was the sudden change from green to black within just 2 days that got me tweaking my setup. For now, I will just observe how well these CFLs perform.


Well nutrients did not change. Apparently it just does not like that photoperiod.

I wouldn't say nutrients did not change, it did. But I think you were refering to my nutrient cycle that did not change. My weekly water change on tuesdays will get nitrates down to 20-30 and it will eventually rise to 70-100 by the end of the cycle. That for sure hasn't changed since I've installed the scrubber.

Yeah they probably didn't react well to the new photocycle, that's why I've changed back to 20-4 for now with the CFLs just in case.


Here are the pics I took yesterday before I cleaned all that black algae off. My screen is now bald on both sides and lit with CFLs.

This was 1 day after the new photocycle (7-1). It started turning black at sides and corners.
http://farm4.staticflickr.com/3747/9083726731_3607a27229_z.jpg

2 days after new photocycle (7-1). I decided to clean all that black sh*t away.. annoying
http://farm8.staticflickr.com/7403/9094558092_de905ea6b4_c.jpg
http://farm4.staticflickr.com/3685/9094553176_f06dfe23e2_c.jpg
http://farm3.staticflickr.com/2866/9094563554_7755fa78a9_c.jpg

Will update with some pics again to show how those CFLs fair.
Thanks for all the input :) Cheers

SantaMonica
06-20-2013, 09:51 AM
It just need more light.

Andy_cy
06-20-2013, 10:14 AM
It just need more light.

Well, since day one I have been using the same lighting, able to get a nice even green mat.
It's only after changing the light cycle and removing the small diffuser over the 20w led chip, then it became black.

Floyd R Turbo
06-20-2013, 10:32 AM
So, more light actually turned it dark.

I think it's important to note that you still had a lot of green growth. The "black, oily" growth that has been referred to in the past as the indicator of high nutrients, needs more frequent cleaning to avoid shading of algae underneath it, etc, may not be what you are seeing here.

When I first fired up my UAS test box, I got a lot of dark stringy growth - like dinoflagellates (SW). I noticed that once I got a base of growth (green) going, if I increased the photoperiod, there was a point where the dino growth took off, and if I lowered it beneath that point, it was not as much of an issue. Still there, but not an issue.

I would agree that you want to clean off the dark growth, but if you're still getting the green growth, then it's not nearly as much of a concern - just let it be. I do. I still get the dark slimy growth on some of my screens. I think there is a relationship between how much of this growth you get and how much flow and light you have.

You may have had the right balance of flow and light with the LEDs and diffusers, so you didn't get the dark growth, but you didn't get enough of the green to filter to your liking.

Add more light by removing the diffusers and lengthening the photoperiod without increasing flow, and you now set conditions for the dark growth to fill in.

It is just a theory that fits the facts, but this isn't the first time I've seen it - personally. It is however the first time I've seen it happen in FW.

Let's see how the CFLs do though. I am interested in that result as well. But if it's no better, then I would plan on going back to LEDs, no diffusers, and increasing the flow.

joelespinoza
06-20-2013, 09:15 PM
Not really a solution to your immediate problem... but anyone tried growing java moss in a FW algae scrubber? Once it gets going It clings to a roughed up screen pretty well and hair algae, or hair algae like epiphytes, can grow directly on it.... I am not saying it would be the primary nutrient export, but you might get more surface area for hair algae growth. At the very least you could toss some of it in the bottom of your scrubber below the screen.

Just a thought.

Andy_cy
06-20-2013, 09:51 PM
I think I kinda know what went wrong. Upon removal of the diffuser, the led chip produces light concentrated in the middle of the screen. The reduction of light at the sides caused the algae to either die off or taken over by dino. The diffuser not only dims the light on central zone down, it also disperses light to the peripheral. With the even lighting, green was able to grow everywhere.

I will start a new thread to chart the growth of my screen with the new lights.

Floyd R Turbo
06-21-2013, 07:33 AM
Hmmm...could be, but then I would have expected a ton of center growth. Did you see that area increase a lot?

Andy_cy
06-21-2013, 08:41 AM
The central zone didn't get much thicker but it's noticeably green.

Anyway, I've tested my nitrates today and it's around ~30mg/L. Shocking because its in the mid of the week, 3 more days to weekly water change. And for the past 4 days I've been feeding more. Arowana gets one additional 1.5" bullfrog per day. Shall do a test again on Monday night before the Tuesday water change.

Floyd R Turbo
06-21-2013, 09:07 AM
The plot thickens

importspeed
06-21-2013, 01:31 PM
Hello.
I just wanted to put in some input comparing your results to mine as far as growth is concerned. I have been running a freshwater scrubber for about three months now, originally it was a uas with cfl lighting, about a month ago i changed it to a submerged (about 5 inches) horizontal with cfl lighting, and about two weeks ago i put a kessil h150 red led light on it. One thing I noticed is that the cfl produced mostly green hair algae, and since changing to the red kessil it has turned into a much darker form of algae. True the algae was the vivid green hair algae that everyone says is great with the cfls, but even though the algae has turned very dark with the leds i am getting nearly 3-4 times more harvest growth and what I harvest seems much more dense. I cannot really compare water parameters at this time because nitrate and phosphates are leaching out of my decor, and probably will be for a very long time. I hope this might have been some help in finding some sort of solution or insight.