DIY Upflow Issue: Need help from gurus

[ChrisOaty]

Ok, so I got into algae scrubbers a long time ago (8ish years) with my freshwater tank and it worked marvelously. I haven't done a water change in over 6 years on my 60g because of the nutrient export of my waterfall-style cfl-lit scrubber and an anoxic filter basket. Water is crystal clear, and I've only lost one fish because he found the only spot in the hood he could jump out of the tank from. That being said, I have tried to employ an algae scrubber on my reef (just moved it upstairs a month ago). In the past, I've tried a large number of variations (waterfall, upflow, horizontal) lit by most of the available options (incandescent floods, CFLs, LEDs, etc.) with very little success. I'm using the standard scratched up plastic knitting screen that everyone's using and I seem to only be able to 'discolor' it, and build up what looks to be detritus more than anything. However, algae in the display seems quite happy and healthy. My current setup was built just before I moved my tank upstairs and consists of five 660nm 1w LEDs attached to a small fan-cooled heatsink on the dry side and a 4"x5" oval-shaped screen on the wet side, all held against the glass by sealed neodymium magnets. Both parts are coated in an aquarium safe water-tight layer of black rubber to eliminate the red bleeding into the tank at night. I'm pleased with the asthetics, as I think it looks quite sharp. You can't see from these pictures but the wires on the dry side. The bits of algae you see are what I seeded it with weeks ago, and to my eye, it hasn't really taken root. I only have two black and white clowns and a six line wrasse which get fed a couple pinches of pellets daily. My cleanup crew can't keep up with the algae growth in the display but the fish seem happy and healthy as do the coral (red sea pulsing xenia, scroll coral, zoas, gsp, duncan, frogspawn.

Pics:



Advice?

[SantaMonica]

Welcome.

The problem with this scrubber is the lights; I'm assuming the bubbles are strong.

The light is too concentrated in the middle, burning it, and no light on the edges. So the middle can't grow, and neither can the outer. Also the 1w probably need to be 3w, although that is secondary to the position. Lastly is the optics of the LEDs; hopefully they are 120 degree or more (the flatter the lens, the better).

A quick partial fix can be done by just placing a diffuser over the LEDs, and painting the insides of both compartments gloss white. But this would just prove that it needs a full fix

[ChrisOaty]

Yes, the bubbles are plenty strong, pulling plenty of water past the screen. I thought it might be the light but figured I'd give it a try since you use 3w which output more intensity than my 1w. The driver I bought (china) says it can run 4-7 1w LEDs. This, however proves incorrect as it blinked if I hooked up less than 7. I think I'm going to grab a larger heats sink and spread 4 of them out more and get rid of this stupid driver. Can you suggest a diver that will run 4 or 5 LEDs? (My moonlight runs on the same circuit/schedule) as the scrubber.

[SantaMonica]

For 1w there are drivers at rapidled I think, as well as 3w. Also for 3w we have some at www.santa-monica.cc/Parts_c_12.html

[ChrisOaty]

Thank you for the suggestion. I've dealt with rapidled before, good guys there. I'm going to call them tomorrow to ask about their moonlight driver which will output down to 0v, meaning I can run a single LED if I want. Until then, I've sanded the lenses on the LEDs themselves and added a plexi cover which I sanded on both sides to act as diffusing layers. We will see if that helps at all. I can already tell that the light is spread out much more evenly, but it may still be a bit too much light. I'll post an update in a few days. Thanks for your help SantaMonica.

[rleahaines]

I have had good results with a piece of diffuser plastic - the plastic diffuser used for ceiling lighting works well to spread out the light.

You can find this stuff at Home Depot or similar stores.

You also may get the same results with several layers of clear plastic wrap or from plastic bags.

[SantaMonica]

Or maybe wax paper.