What are your nitrate and phosphate numbers? And with all that algae, I wouldn't be a bit surprised if they are zero. But that's a start. How long have you been running biopellets? Also, how old is the tank....this kind of thing is a right of passage in young tanks.
Cut back on feeding....maybe once every two days (unless you have a variety of fish that require more feeding).
NO3 tested now came zero..PO3 came out. 0.25 ..week ago I started running two little fishes biopellets.on my media.. I only.feed once every other day..tank it's lime 2.3 yrs.. I had running gfo then switched to biopellets week ago
Although not usually recommended, I'd continue running GFO, with such a high Phosphate number. Biopellets won't work without a relative higher nitrate level versus phosphate.