Been running mine on FW for a couple of months with some success.

See here viewtopic.php?f=3&t=162

I suspect that there is not as much potential benefit (per square inch) for FW as with SW though as you don't get those large seaweed type "turf" macro-algaes in FW.

It may be that, limited to hair and "slimy" algae we will need a larger lit surface area than is necessary on SW systems.

We'll see.


So far, while not really seeing a dramatic fall in tested NO3, I have seen benefits in less algae in my display tank. And that small amount of algae that does still grow there is of a "softer" and thus easier to clean variety.

I used to get quite a lot of that hard "spot algae" on the glass which could not be removed without putting my hand inside and scraping or manually scrubbing it off. I don't get that now. The algae that grows in the tank now is more of a powdery type which comes off easily with a few passes with a magnetic glass scrubber.

I also removed a white rock which was absolutely green with algae two or three weeks ago and cleaned it by boiling. I put it back and there has been no significant algae re-growth on it since.

Since my NO3 has not fallen dramatically I suspect that the reduction of tank algae may be due to the scrubber reducing phosphates (which I haven't tested for) or perhaps some other trace nutrient(s) that algae needs to grow.