Thanks - they are easier on plants?? How many discus would you suggest?
Not exactly, its just that juvie discus require super clean water and are best raised barebottom with nothing in the tank (for easier water changes) to prevent stunting. Just how clean water? 50% water changes a day, better yet, make that 100%.
They also need very frequent small feedings (5-8 times a day) with high quality, varied foods such as frozen blood worms, live blackworms, homemade recipes, ect (use an automatic feeder if you aren't homw 24/7). Adults are definitely more pricey than juvies, but unless you want 4inch fish at adult size, start with adults. Or you can raise juvie discus in a separate barebottom tank.
As for how many, I'd say 9-15 depending on how much you're willing to do water changes and if its going to be a species only tank. A planted tank is generally harder to clean than a non-planted one. 15 discus is the maximum amount of discus you're going to be able to fit in it, though I wouldn't. I would go with 10 discus with some cardinals and a bn pleco.
With 10 discus, some cardinals, and a bn pleco (maybe some otos), I would say to do 25% water changes 2-3 times a week. As for water parameters, keep the nitrate below 20 or 15 and the temperature at 86F.
Lastly (I know I'm rambling!) one of the most important questions: where to get healthy discus? I would suggest Kenny, he has very healthy and happy discus and he is very serious about his work, I've never heard of someone getting a DOA. His website
http://kennysdiscus.net/. However, he's very popular so his shipments are sold out pretty quickly. A good discus site to visit is
http://forum.simplydiscus.com/, you'll find lots of helpful people that will answer any questions you may have.