How heavily planted is the tank? Sounds like you're dosing quite a bit of ferts. If you dont have enough plants to use them up then you wind up just feeding algae. Also at low med light may not be enough to drive the plants to utilize that level of fertilization, regardless of co2 levels.
Disclaimer: Im no expert, definitely still learning planted tanks myself. Those are just some ideas that jumped out at me. Hopefully someone else can come along and better diagnose the problem(s). Pics would probably help too.
Disclaimer: Im no expert, definitely still learning planted tanks myself. Those are just some ideas that jumped out at me. Hopefully someone else can come along and better diagnose the problem(s). Pics would probably help too.