OK, here's the lowdown on my ATS...
My Tunze 9002 collection cup normally obscures this view, but is removed for these pics.
My ATS consists of four DIY parts:
- The LED Light - 12 LEDs mounted to a heatsink. My LEDs are a mix of 9 or 10 Cree XR-E's mostly Cool White, sprinkled with Warm White. I've also got 2-3 Osram 660 nm deep reds. They are powered with a Mean Well LPC-35-700 constant current driver. FWIW, I had a previous all XRE Cool Whites that I spilled water on (bad idea). It worked very well also. Current thinking is that you need all Osram 660 nm deep reds. This proves otherwise.
- The Algae Mat - This is sheet of nylon hobby screen (normally used for knitting or crocheting I think) inserted into a modified piece of PVC. The screen was massively, manually, abraded with a hole saw bit to rough it up allowing algae a better chance to adhere. The screen is inserted into a slot cut into the PVC, and remains there because of a couple of nylon cable ties to secure it. Water pours out of the PVC onto the screen, keeping the algae under a flow of roughtly 300 GPH. The portion of the mat that is not submerged, getting most of the light, is 8" wide by 6" high.
- The Plumbing - This is just a piece of 3/4" PVC with a slit cut long enough for the screen to be inserted, roughly 8" long. The width of the slit is rather important, and I don't recall its width. But pls check this monster thread for details on building one yourself. The PVC is capped on one end, and the other is supplied water by a "T" off my return. I've installed a gate valve on that "T" to better control the rate of flow to the algae mat. And to help remove the algae mat for weekly cleaning, I put a union on the PVC connecting it to the line that feeds it water. And that line is not hard PVC. It's flexible - reduces vibration and helps removal.
- The Splash Guard - This is just a 3-sided piece of acrylic that goes between the algae mat and the LEDs. Splashing salt water it bad for LEDs.
. I bought my acrylic from Ridout Plastics, who will cut the pieces for you for little to nothing. The pieces needed to be bonded with IPS Weld-on #4, which they also sell. You might also get a plexiglass drill bit to make the holes for hanging, though a wood bit might work too.
Placement in my sump is simple. Everything hangs from hooks. The LED has hooks mounted to it, that hang from screws on the inside side of the stand, making it sit nearly flush with the sump wall. A few inches away hangs the splash guard. And nestled inside the splash guard is hangs the algae mat. The surface of the LEDs is 3 and 1/2" away from the algae mat. Further will reduce growth. Closer may burn the algae. That is a critical dimension. I'd guess a tolerance of +/- 3/4". But that's just a guess.
As previously mentioned, the typical ATS has water flowing down both sides of the mat. It's simpler, but it takes more room because it means lighting both sides of the mat, and algae growing on both sides. I went with water and light on one side only to reduce room in the sump. And with my powered by my return, it need to be over-sized to accommodate this extra flow need. You can just as easily feed the ATS mat with its own dedicated pump. Or even have it fed by your drain. They all work.
Here's the algae mat, removed for cleaning.
And the splash guard, right after cleaning this morning. It needs a good 60 second cleaning every few months.
This is obviously scalable. Mine works for a light-moderately fed 40g system. Other sizing info can be found in the thread I previously referenced - revised sizing info toward the back. But what I have works. If you had a system that was 80g in total you could make a mat that was 16" wide by 6" deep (not submerged) with 24 Cree XREs (WC and/or NW) placed 3.5" from the mat, with 600 GPH water flowing across that mat. You'd grow algae like nobody's business.
I previously mentioned pod growth as a side benefit. Here's one I pulled out as I was cleaning it today. It's all curled up, and looks like only 6 mm, but stretched out it's 10+ mm - a big boy. I get this an many more to go into my DT at every cleaning. Though it's likely unnecessary is their tiny progeny are reputed to be washed off the mat, and pushed to the DT through the return.
You can go nuts building an ATS, but I tried to observe KISS, and it has worked out well. If I ever lose my LED array from splashing I'll make a splash guard for it too. But for the last 6-9 months having the splash guard in front of - and along the side of - the mat seems to work just fine.
Its too bad I have cyano right now, because I cannot attribute my current zero readings for NO3 and PO4 to the ATS. But it did it for my old tank, and as soon as I get past this "new tank syndrome" with no more cyano, I'm absolutely certain I'll be able to show you both zero readings, and an algae free tank. Except for in the ATS that is.
