I keep 5 discus in a 72 gallon bowfront with a wide variety of plants that grow like crazy. I keep my temps at 84 degrees and my tank is full of vals, anubius, java ferns, bacopa, rotala indica, red ludwigia, a large aponogenton as well as some dwarf chain sword.
As far as CO2, I don't use CO2, instead I dose flourish excel using an eheim doser and everything grows great.
As far as CO2, I don't use CO2, instead I dose flourish excel using an eheim doser and everything grows great.