algae scrubber

[treesprite]

Any ideas on making a built-in algae scrubber behind a false back, with like a drop-in screen thing?

 

I never started work on the 120 I got, and may ultimately not keep it (still not sure about moving situation) , but am thinking maybe I can play with it at least. I was having second thoughts about using the CL holes, but I don't like seeing the caps over the CL holes. I also wasn't settled on overflow. I considered putting in a false back if I could justify it by design, partly because I have a glass panel from a 75 g I had broken 6 years ago, partly because if I don't do CL, I don't want to see the caps, and partly because I liked having the false back in a hex I used to have.

 

The 120 is 24" deep compared. to the 18" deep of my 75 which is the same. length... I don't mind the idea of using that extra 6" for something besides display depth. It just suddenly popped in my head that it might be a good space fof an algae scrubber.

 

Note that this is a notion off the top of my head while suffering from a bad cold, side effects of medicine, and lack of sleep.

Edited January 2, 2016 by treesprite

[treesprite]

Sitting here drawing, getting ideas (too roughly done to post) . This is all just I the event I am up to the challenge of doing it... will probably not, but I like this idea so far.

 

The overflow behind the false back would need to be situated to use the CL holes as tank exit holes, which means either 1. the overflow would either be 2/3rd length and algae screen only 1/3 (too small) OR 2. overflow could be centered with 2x algae screens (one on each end); just means 2 pieces of glass for overflow sides instead of just 1 (front is the false wall, back is the tank wall).

 

The teeth at the top of the wall could dictate the flow rate, since the algae screen ends need very different flow rate. Teeth would basically have just very thin spaces between then for screens, while normal width apart for overflow section.

 

The algae screens would be tilted, the tops resting against the inside of the false wall, under the teeth so water coming through the teeth could flow over/on/down the screens.

 

I don't know if the screens are going to work well if fully submerged in water, but I'm not sure how I would make the water levels on screen ends be lower than the water level in the overflow (Somehos, water has to get from the screen sections into the overflow, and I'm not sure how to accomplish it if the water levels need to be different).

 

I could drill a couple return holes in the false back, which would mean returns would go through the that back section... not yet thought out how I would be able to do it. Wouldn't necessarily need bulkheads in them. Wondering if I could make some kind of dual use on them.

 

I would need to paint the false back, but would be able to strip the paint off the back of the tank to I could put the algae lights behind there, then none of that light would get into the tank like it would if I just stuck the lights above the screens which would only give good light to the panels at their top halves.

 

This could actually simplify things by allowing elimination of a refugium.

Edited January 2, 2016 by treesprite

[treesprite]

It's at times like this, that I can really feel my reef geekiness.

[Origami]

A drawing or drawings would help the description, Forrest.

 

Algae turf scrubbers work best with (1) light, (2) dissolved carbon dioxide & oxygen and (3) an attachment surface. And nutrient-laden water, of course. Most ATS's have a diffuse flow of water going over a screen hanging in open air. Some may use a bubble wand or similar aeration device if the screen is submerged to saturate the water with gasses in the screen area for the algae.

 

Paul B. uses an ATS that's (in essence) a very slightly tilted trough, lit (today) by LED's and lined with a roll of window screen that has been treated with a little cement to give it a rougher texture. I think that his basically sits on the back edge of his tank, across the full length. Other ATS's that we've all seen, hang some window screen below a perforated PVC pipe with water flowing through the pipe and down the screen.

[dave w]

The good news is that as long as you have light and decent water flow, almost any setup will house an algae filter if you put in a screen.  Even without a drawing, your description seems like it will do fine.  Just try to get as much light on the screen as possible, and as much flow as possible.  Nature will do the rest.

[paul b]

I don't know what you are looking for but I built this over my tank.

[treesprite]

I must have gotten people's systems mixed up, because I thought you had a trough-type thing. So how does that work over your tank?

 

When I had a false back before, in a 42 hex, I had it packed with macros. I've had tanks with sectioned off ends packed with macros also. Those were all secondary tanks, and they always had better parameters than any main tank I've had; I think having the algae right in the tank helps a lot more than having it in a refugium, though I'm not sure why when it's all the same water.

[paul b]

I do have a trough type thing. That and this are just experiments so now I have both. This is a screen where water flows over and there is a light near it. It grows algae then I un hook it, put it in a sink and scrape off the excess algae.

[treesprite]

I finally took some time to try to learn more about ATS, since I'm obviously thinking I could do something.

 

If I were to lean a screen against the inner wall (aka giant overflow), with the top of it directly under the overflow teeth, would the screen being there be able to prevent the type of waterfall noise I get from my internal C2C overflow when I have the water height adjusted too low? If that would work, I would be able to keep the water level lower so the screen is not fully submerged (the holes in the back are slightly lower than halfway point).

 

Would a large screen actually be OK with flow going over it that is from my return pump rated about 15,000gph (- 4ft hl), which is/ would be spread over a 48" C2C OF? (algae grows between the teeth of my current C2C OF with that high flow, so I'm assuming it would be OK going over screens.) If so, the ATS could actually go C2C (but divided into multiple smaller screens to make a gap for a couple drain pipes, and to make the easy to pull out to clean). It would be a lot simpler than all the complications I've been tossing into design. There would be no need for an extra pump just to have water flow down a screen, I wouldn't have to deal with pvc (just have to use something to keep the screens in place and straight), and I would have a much bigger ATS (figuring gaps for pipes, guessing about 40"L X 20"H, though half submerged).

 

I guess none of this will happen if I can't get the center brace/top trim off the tank... the tank is in Gary's barn about 20 miles from me, so I can't check out that issue right now.

Edited January 4, 2016 by treesprite

[AlanM]

I kind of do the lean thing you suggest. I took a couple clips and connected some plastic canvas to a sump baffle. The water flows over the canvas and a light shines on it, the part that is above the water surface grows like crazy. Long algae. The part that is under the surface doesn't grow much, but gets a nice sheet of bubbles that is fun to see. Point is that Tom is right, the scrubber does better with exposure to air with an air stone or suspended like in Paul's scrubber.