Here is the algae reactor I made out of an aquamax I wrapped a red and blue Led strip around the outside of the reactor then covered that with black Vinyl. It's pretty small so it fills up quick, I put in around 1 inch of chaeto at the bottom and it will be completely full in a week. I turn it on whenever my tank lights are off so about 14 hours a night.
This reactor is enough to give my 120 gallon system stable no3 and po4. I no longer need to dose carbon or run GFO. Obviously mileage may vary.
Inside
One week's growth
Two Little Fishies ATLPBR550 GFO PhosBan Reactor 550 https://www.amazon.com/dp/B004I6U192/ref=cm_sw_r_cp_api_7P9nBbP72BWVD
How long did it take for the reactor to work? I set mine up last week and my nitrates are now 20ppm higher than with my canister filter where I used to run nothing but carbon. That's clearly proof enough that canister filters are not nitrate factories.