I want to use my 180 litre tank to keep four discus and 15 rummy nose tetras.Which water is the best to use HMA or RO.Whats the best diffuser to use with my JBL CO2 kit.I will be using a aqua one regency 80 tank with tetra complete substrate and eco complete planted aquarium substrate from carib sea with under gravel heating.The lighting will be provided by two 20 watt hagen power glow tubes.what hardy fast growing plants should i use to plant the aquarium out.A lot of questions i know help please????