vahegan's UAS test

[vahegan]

I have finally made my experimental UAS today. Sorry for the poor quality of photos - made with the iPhone, was too lazy to pick up a descent camera with proper processing.

For light source I used the Surexi F1 LEd modules with optimal for photosynthesis spectra, purchased at the TheLedStore. Initially I planned using these for a first generation ATS, but never managed to actually finish building one. Since this new design was much simpler to make, I decided to give this a go - although I believe that the old design might be more efficient (since at least, there is no light loss on the thick glass and the algae that will grow on it). Anyway, if I don't like this design, I can always take out the screen convert it to the old style scrubber.

Here are the Surexi modules, the match box is for size:

The F1 spectrum module contains 12 red LEDs (with 660nm peak) and 4 royals blues (450nm). Each module is good for up to 5W power, made in wet-proof case (IP66) and has an integrated 60 degrees lens.

I cut 4 50cm long and 6cm wide aluminum sections to serve as the construction base and a heatsink for the LEDs.


I attached the sections to each other with rivets, then drilled holes and tapped threads to attach the LEDs (using a thermal compound, of course).


I attached a low-cost chinese driver on the back. It is capable of up to 90V output at 300mA. All the LED modules were connected in series, with 10V voltage drop on each. This present setup yields 24W of power, if I replace the driver I can safely get up to 40W power from the same LEDs, but I believe there is sufficient light already, to start with.


I processed the canvas like a cactus using the saw, as SantaMonicsa suggests in FAQ. I attached an airstone on the bottom using plastic ties, and then I hung the screen on a plastic rod.

[vahegan]

I hung the screen near the side wall in the sump, resting the plastic rod on front and rear walls of the sump, connected the air pump and turned on the LEDs. The photo isn't good since the light is too strong.


My tank is presently algae-ridden and I hope that all these algae will gradually move to the screen.
The tank is 250l (about 65g) mainly soft reef with Deltec MCE-600 skimmer, a Blue tang, a Premnas clownfish, and 2 mandarin dragonets. Daily feeding of one frozen cube and about as much live tubifex worms (mainly for the dragonets)





I will report in a few days if there is any progress.

[kotlec]

Few weeks is more realistic schedule.

[SantaMonica]

Good first try.

One thing, with any scrubber, you want to try to not have any area of the screen that does not get bright direct light. Area that get weak light will grow dark, die, and reduce filtering; thus the the larger areas will actually make the scrubber weaker. If possible, re-do the screen so that all of the screen is within about 3 inches of an LED.

Also, for one cube a day, a 1-sided screen side of 24 square inches (4 X 6) is probably best.

[vahegan]

Few weeks is more realistic schedule.

Yeah, I mean, I hope to get any growth at all on the screen within a few days.

Good first try.

Thank you, SantaMonica!

One thing, with any scrubber, you want to try to not have any area of the screen that does not get bright direct light. Area that get weak light will grow dark, die, and reduce filtering; thus the the larger areas will actually make the scrubber weaker. If possible, re-do the screen so that all of the screen is within about 3 inches of an LED.

Yeah, its about 2" between the LEDs horizontally, and about 2.5" vertically. The screeen extends some 4" up the first row and as much down the lowest row. So it basically fits within your recommendation, except for an extra inch on the top and on the bottom

Also, for one cube a day, a 1-sided screen side of 24 square inches (4 X 6) is probably best.

Well, the effective size of my screen now is about 10"x11" which is about 4.5 times more than you suggest.

Please note, however, that besides one frozen cube daily I also feed about as much of live tubifex worms soaked in Selcon, for the dragonets. Selcon adds a lot of phosphate. At least, in my previous system (which was half of the volume of present one) the phosphate went very high (about 2ppm) within a few months after I started feeding the dragonets - so that I had to dose Lanthanum chloride to get rid of it. I don't want to repeat this in the new system and I hope that the scrubber will help me to keep the phosphate under control. I want to be on the safe side and I'd rather have some extra scrubber power at hand before its too late. Besides, I am not sure yet that this type of UAS will be as efficient as conventional ATS.

[vahegan]

Watching the screen carefully this morning, I have noticed a light brown tint on the "cactus needles".
Absolutely not visible under the bright light, but distinguishable when the lights are off. So I hope, it is gradually starting up...

[SantaMonica]

Not bad for one day.

[vahegan]

Daily update: Inspected the screen again this morning. Virtually the same as yesterday. Maybe the tint is getting more even throughout the screen and slightly darker, yet it is still barely distinguishable and again, only when the lights are Off.

[vahegan]

Update: The screen is getting darker brown - clearly visible when lights are Off and barely visible under lights On. It is yet far from being anything scrapable, however.

The pic shows it to some extent, though not very clearly:



Also, after two more days, I noticed a strange thing today: it seems to me that there is more algae growth on the edges of the screen, where there is less light falling and less bubbles rubbing it. I can think of nothing that would explain this...

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I have an idea: Instead of the air wand, why not use a smallish (something like 250-300l/h will do just fine) internal pump, with an air line entering near the impeller? Will probably also need something like a bubble plate to distribute the bubbles evenly, like they do in skimmers, but maybe in a compact area around the screen this won't be even needed. The benefits are: no need for a possibly noisy air pump, a better flow of bubbles (accompanied with a better flow of water), and an all-integrated solution. I am planning to add a mirror to my setup - the screen will become enclosed between the mirror and the wall then - I can give the pump a try at the same time. What do you think?

[Floyd R Turbo]

Per your post on my thread, you might try the diffuser grating. You can just put one matchbox-sized piece on the glass in front of each one, or one piece covering the whole area (which is probably easier). You can find that material in a hardware store that carries ceiling tiles (like the ones that go in a 2x4 recessed grid ceiling). It's called a "prismatic diffuser" and is actually what they use in some light fixtures ("troffers" is what we call them here)