Yes, you should be using flourish or some other liquid fert in addition to root tabs. Some plants feed more from roots, some feed from the water column. You'll want both.
Plant 1 - Red - this is a guess - ammania mauritiana
Plant 2 -Lloydiella, aka Lysimachia nummularia
Plant 3 - Cabomba caroliniana
Plant 1 - Red - this is a guess - ammania mauritiana
Plant 2 -Lloydiella, aka Lysimachia nummularia
Plant 3 - Cabomba caroliniana