well this is just stupid isn't it? why can't you just answer the question asked? no amount of, 'your doing it wrong' 'your overstocked' 'you dont care about your fish' is going to help anyone really is it, and making childish comments like red tailed catfish etc is never going to get anyone anywhere is it.
he wanted answers about discus, and obviously 90% of you don't know anything about them, so therefore shouldn't of taken it further then just reading the post.
it is definitely not the worst case i have seen of neglect! i think the majority of these comments should be aimed more at people that keep fish is vase's, buckets, tubs etc.
absolute stupidity.
as mentioned by the couple of sensible people, discus are mainly bred in bare bottom 'cube' type tanks with sponge type filters so as not to produce too much flow, and a single breeding cone, normally in the middle.
i can't help but feel sorry for the fish kept in simple boring tanks like this though, it would be enough to drive a fish mental! no life, may aswel be in a box.
i would set up a 4 foot tank, about 15" wide and 18" high, set up with fine sand, plenty of long plants and root style wood for them to breed on. other inhabitants who can cope with the 30 celsius temperature are rams and cardinal tetras, though rams may eat eggs, im not sure. but cardinals are commonly kept with discus and make a stunning display.
if you want them to breed you will need very good filtration, and keep to a strict cleaning regime, including gravel vacs and big water changes.
good luck