I feel your pain. I had BGA for nearly 3 months. I almost gave up. I had to make many changes. FIrst of all my tank even though small is heavily planted, 10 gallon. I tried to get away with a zoo med 501. rated for 30 gallons. Sure it is. The tank was not only getting overrun with BGA I had diatomic algae blooms that was producing more o2 than my plants, My canister filter was poring O2 out like crazy. I started loosing shrimp. I tried peroxide in the substrate & manual removal. My tanked even had a foul smell & I felt sick being around it.Nothing worked. I was loosing it. Than I decided to run an oversized canister filter & leave the underpowered one in place. (CARBON) in both filters. Than I changed my bulbs to 6500K. I did 50% water changes every week sucking out from the substrate. Than I kept my NO3 at 10ppm or more. My PO4 was kept from crashing at .25-.75ppms at all times. I made sure all my ferts were inline. I targeted DOC's & flow around plants & substrate as well. I used the cred card trick. Take a credit card & slide it down almost to the seal of the tank & slide all the way around most of the tank. This helps aerate the substrate. I even poked some holes in the substrate itself. Make sure there is some surface agitation itself as well. Very important. Lastly even though I reduced it to 99% gone it still tried to survive. The very last thing that beat it down was an antibiotic called flagil. After dosing for 3 days it gone & my tank is crystal clear CRYSTAL CLEAR & hardly any algae at all. The tank appears perfectly balanced & I owe this in part to TOM BARR. Look him up, he knows what he's doing. I hope this helps.