Cutting the light period and intensity is usually better than messing around with other parameters first.
Light is the driving force. More light = more requirement for co2, more macros (NPK) and more trace elements.
If you want to maintain high light levels then you have to up all the other elements and few people maintain tanks for long periods with all the unessarry work associated with High input requiring tanks.
All my aquariums have 6-7 hours duration of light, typically 30-40 PAR at the substrate. Beyond 8-9 hours, I dont see the point. It is not necesarry unless you like being charged for leccy that you dont need to use.
I wouldnt waste money on phosphate removers. You can balance your system without such desperate measures.