More water changes, that's what I do. I determine the amount/frequency of water changes based on NO3 level, I try to keep it not much more than 10ppm MAX. High PO4 brings out red nicely in some plants for me, like rotala macrandra.
Truvu 100g Flourite, wet/dry, AHSupply 302w PC, PinPoint controller 10gallon15w T6+15w T8 55gallon40w T6 ODNO4x, no CO2. Discus grow out.
10gallon Tonina tank, 2x15w T6 ODNO 4x
I will do aquascapes after I collect all the plant species and grow them to perfection.