I built and started up a scrubber today.
I have a 30 gal high reef aquarium with a few fish and mostly soft corals. The aquarium has been up and running using a sump, and a skimmer.
For quite some time I have had problems lowering nitrates.
http://i1230.photobucket.com/albums/...crubber003.jpg
At the present nitrates are about 180, and I have no idea about phosphate. I am assuming it is high as well because of problems I have keeping some kinds of corals. The soft leathers seem to like the soup they are in.
I have an old backpac refulgum that I tried to use 5 years ago to grow macro algae, didn't work very well. I modified it to put in a scrubber fairly easily. Basically all I needed to do was to get some pvc, a valve, some plastic canvas and so some minor surgery on one of the dividers. As others have said, cutting a slot for the screen was the hardest part. I didn't have a hole saw, so I ended up using a normal kitchen grater - worked pretty well - to rough up the plastic screen.
As this tank is only 30 gal I need only 60 sq. inches... the screen I used is 10 X 12' so it should work as a one sided scrubber.
http://i1230.photobucket.com/albums/...crubber001.jpg
I sent away for a red and blue LED grow light from a firm that sells that kind of thing to people who grow their own. It's 12" by 12" and can be set next to the box on the floor of my cabinet easily. No need for a fan. The light was only $24 so if it doesn't work, I am not out much. I have CFL bulbs and fixtures around the house if I need to use them.
Total cost to date - about 8 bucks for the PVC, elbow fittings, valve and less than a dollar for the plastic canvas. So not counting the gas back and forth to Home Depot and Michaels - about $33 so far.
Got it started tonight. Everything seems to be working.
http://i1230.photobucket.com/albums/...crubber005.jpg
I will post progress.
Rick