I have a discus and tank question please. I’m very new to discus and caring for them. The guy who works at the pet store told me that I could care for two medium discus &amp; five cardinal tetras plus two bottom feeders comfortably in a 15g tank, I was wondering if he’s correct. I’m currently looking at a 33g tank and wondering if the same amount of fish or plus one more discus would be okay and live nicely. 