Here is majority of the things that i have learnt about Discus over the last few months, now that i'm trying to breed them!
They are found In the Amazon River in South America and that they are a peaceful carnivore, which love to be fed with live food such as small bugs, mosquito larvae, tubifex worms, blood worms and flakes! The enjoy deep tanks not long tanks for they aint the most active of fish. If using a large longer tank it should be heavily planted with lots of driftwood/rocks which allow them to shelter in. A temperature range between 27-30 degrees celcius and a PH level of no less than 6 and no greater than 7.5 is ideal, weekly water changes and excellent filtration is also very handy! for they arn't a very hardy fish!
Discus prefer to be kept in schools, i have 6 together and they love it! when i first started i only had 1 and it died
As for breeding (ive nad no luck) but i've been told by my discus dealer that if i up the temperature a little bit and have clean pieces or rock/slate that they will eventually lay eggs on it! And that the fry actually feed off the parents slime coated body!
They are 1 of if not the most colourful freshwater fish that exists, also reasonably hard to breed (why there so expensive) prolly not a fish for beginners!
Hope my information may be of some help when buying discus