Basic newbie questions

[torch]

Is it possible to feed only pellets only. I don't want to go live or frozen food. Does this apply to young and mature discus?

Next debating going with either 40 gallon or 50 gallon tank? How many young discus to get on it

hydro sponge 4 using air pump or power head. If not sponge how about aquaclear hob filter?

What is lowest temperature for keeping them?

[MrsIHguy]

No matter what size tank you get, you'll wish you would have gone bigger! Just remember basic guideline of 1 discus per 10 gallons. And discus prefer groups of 5+... I've always kept my tank at 82, and most discus keepers will say a variety of different foods is best. I feed pellet, flake, freeze dried and frozen.