In the last 5-6 month I was very much focused on GSA, on Anubias and Cryptocoryne parva leaves.
Someone on this forum had a problem recently with C. parva while dosing AquaCare+NPK (good CO2,EI, etc)
I had the same problems for some time now. I started dosing, together with AquaCare+NPK, also KH2PO4.
Here is the result and is working in my other tanks as well;


In the past time, even though dosing often + keeping good CO2 this C. parva would get GSA and some sort of black algae (same as Anubias), but now with extra KH2PO4 no algae at all (with good CO2 or regular Excel).

AquaCare should add more PO4 to their NPK mix.

Regards, Dusko.