Ace's ATS v2.0 - LEDs

[salty joe]

First, thanks for posting your experience with LED scrubber. Do you know at what amperage your LEDs are the most efficent? Down the road I'm going to try an LED scrubber and see what I can do with 100 watts of power. My plan is to run two alternate scrubbers at 100 W each. When one is lit, the other will be dark. I want to light them intensely to push the algae to photoinhibition, at which point the light goes out and the other scrubber gets lit up. The downside is an O2 sensor is a little pricey, but I don't know how else to tell when photoinhibition occurs. I read a paper awhile ago that showed marine algae photosynthesis rates and it was real fast until photoinhibition occurred, then it dropped off like a rock. If anyone is interested, I can try to dig it up.

[SantaMonica]

You are not taking into account the adaptation of the algae. Whatever lighting regime you provide, the algae will re-grow to make the most of it, keeping it's physiological boundaries away from "the edge". The studies you read probably don't take that into account, because it was not their purpose to see what "replacement" algae would pop up.

[salty joe]

You are not taking into account the adaptation of the algae. Whatever lighting regime you provide, the algae will re-grow to make the most of it, keeping it's physiological boundaries away from "the edge". The studies you read probably don't take that into account, because it was not their purpose to see what "replacement" algae would pop up.

By "the edge", do you mean photoinhibition? It was a paper on Cheato, but it was mentioned that most marine algae react in a similar manner. By "replacement" algae, I assume you mean new growth of the same algae, is that right?

Basicly, it was shown that if hit with intense light there is rapid photsynthesis for a period (about 4 hr IIRC) then photsynthesis drops off a cliff until the algae goes through a dark period. My intention is squeeze as much growth from every single watt by taking advantage of that.

[SantaMonica]

No, a different algae that is more light tolerant. Probably lighter in color.

[salty joe]

I am thinking of nailing the screen from the getgo with relatively short periods of light with a similar intensity as the sun. Whatever grows is what I'll be stuck with. Hopefully something will grow. Once the screen has algae established, I'd check the scrubber drain water with an O2 sensor and hope to find a point where photoinhibition occurs and use that time period to alternate between scrubbers. Will it work? I hope so. Lots and lots of hoping. We'll see.

[kcress]

Really nice build you have here Ace! This is exactly where I'm going. I have a few questions I hope you can provide answers for.

1) Any reason not to use silver or white paint? My thinking is why not ricochet the light around until it's intercepted by the screen?

2) How's the water getting out of the screen side? I presume there is gap at the bottom of the partition. How tall is the gap?

3) What flow are you running?

4) Is your partition acrylic?

5) Any little niggling issues that would cause you to do some detail slightly differently?

Thanks!

[Ace25]

Do you know at what amperage your LEDs are the most efficent? Down the road I'm going to try an LED scrubber and see what I can do with 100 watts of power. My plan is to run two alternate scrubbers at 100 W each. When one is lit, the other will be dark. I want to light them intensely to push the algae to photoinhibition, at which point the light goes out and the other scrubber gets lit up. The downside is an O2 sensor is a little pricey, but I don't know how else to tell when photoinhibition occurs. I read a paper awhile ago that showed marine algae photosynthesis rates and it was real fast until photoinhibition occurred, then it dropped off like a rock. If anyone is interested, I can try to dig it up.

Not exactly.. most 3w LEDs are at peak efficiency at around 700mA, which is around 2.1w, maybe a little less. I am running a string of 14 LEDs on a single Meanwell 700mA constant current driver right now. Above that you do not get equal output vs power in, it takes more power to get less lumens. I like the sounds of your experiment. Sounds like a great idea to test out that could lead to even better working scrubbers.

Really nice build you have here Ace! This is exactly where I'm going. I have a few questions I hope you can provide answers for.
1) Any reason not to use silver or white paint? My thinking is why not ricochet the light around until it's intercepted by the screen?
2) How's the water getting out of the screen side? I presume there is gap at the bottom of the partition. How tall is the gap?
3) What flow are you running?
4) Is your partition acrylic?
5) Any little niggling issues that would cause you to do some detail slightly differently?

1. That sounds like a great idea. At the time I was more worried about light proofing it and wasn't too concerned about reflecting light since LEDs are so directional but I still get a lot of hair algae growing in that chamber in the water (which I don't mind, just helps filter more) so adding silver paint first to act as a reflector, then black on top of it to make the chamber black from the outside would be a good idea.

2. 3 baffles, 6" tall on #1 and #3, #2 is top down baffle and is bigger. All baffles 1" apart from each other and are black ABS plastic with a sheet of glass behind each ABS sheet for support (since ABS doesn't bond well to glass, I wanted a glass to glass bond). The first baffle I cut teeth in the top of the ABS like an overflow box and it catches almost all the algae that tries to make it through. To separate my 2nd and 3rd chamber I used a 9" tall piece of glass so the first 2 chambers of the sump are 9" deep (level needed for my skimmer) and the 3rd chamber has the return pump and the ATO float switch, this is the only chamber where the water level changes with evaporation and it is only 6" from baffle to glass, so my top offs happen often and tiny amounts each time, few cups worth, which keeps my salinity levels really steady.

3. Right now I am using my overflow (which I tested and am getting 600GPH) and also a maxi-jet 1200 coming from the other side, up the emergency overflow pipe. Guessing around 200GPH out of that so 800GPH total over the screen.

4. ABS + glass

5. Design the light box a little better. I made it too tight, barely enough room to set lights in them. Polish the edges of the glass on the light boxes, you don't know how many times I have cut myself on them, they are razor sharp. I also made my screen about 2x the size needed for my tank, always thinking "bigger must mean better" but now I am starting to re-think that. I am now thinking bigger may not be better in the case of screen size because if you have one sized for 2x the tank size (or feeding by the new guidelines) and you get the ATS working great, even though it shouldn't, I think you may be adding a lot more DOCs back into the tank than the tank can handle. If I cut the screen in 1/2 I would still get great filtering but more along what the feeding guidelines say I should have size wise. With 1/2 the amount of algae that should mean 1/2 as much DOCs getting released into the water as well. Just my thinking for this week.

[kcress]

Those dividers are a lot more involved than I thought - looking at the pics!

Thanks for the detailed answers Ace.

Now where's my glass polisher....

[kotlec]

I am now thinking bigger may not be better in the case of screen size because if you have one sized for 2x the tank size (or feeding by the new guidelines) and you get the ATS working great, even though it shouldn't, I think you may be adding a lot more DOCs back into the tank than the tank can handle.

Does reducing light on hours can do anything to that ? If it would reduce DOC production , you would have big screen that you need to clean only half often.

[salty joe]

[quote="
5. Design the light box a little better. I made it too tight, barely enough room to set lights in them. Polish the edges of the glass on the light boxes, you don't know how many times I have cut myself on them, they are razor sharp. .[/quote]

Just get a small rock and gently rub the sharp corners, they will dull up in a hurry.