So I think most of us love algae reactors, and I think alot of us have stuff laying around. I re-purposed 2 Aquamaxx Biopellet Reactors into algae reactors and it's the best thing I did for my tanks in years. If you have a small tank and need to choose, an algae reactor is even more efficient than even a small protein skimmer. So here's the stuff I had laying around, some BRS reactors. I easily turned one into an upflow algae reactor. I took a piece of 1/2" pvc and a 1/2" coupler, I honed the inside of the coupler out enough to fit the flange of what was the output of the reactor top. I took the strainer top of the inside canister of the reactor and drilled a 5/8" hole. I glued the strainer to the other end of the pvc, with the flat side towards the pipe. The water goes in through what was the output down the pvc then distributed with the help of the strainer, back up and out of what was the input. I didn't get the lights yet, I will use these:https://www.amazon.com/gp/product/B0132NME6O/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 I have these on one of my other reactors and they work great. So if you have a BRS reactor laying around, a pump that gets anywhere from 150-300gph, and about $20; you're in business.