Discus arent that hard to keep at all...not even wild ones. The basics are warm water (mid 80's) and frequent water changes. Everyone will say something different regarding water changes...but in all honesty, the amount of water changes you need to do will vary on several things. #1: bare bottom or fully planted. In a bare bottom tank, you will need to do more water changes than in a fully planted tank. BUT, discus dont do as well in a planted tank than they would in a bare bottom one. #2: Stocking density. For discus, the general rule of thumb is 1 fish per 10-15 gallons. 110 gallon tank you could easily keep 8-10 discus in there and get by with water changes less frequently (1-2x a week). #3: Filtration. I am a HUGE advocate to using wet/dry filters on all discus tanks because it makes things so much easier and they can handle the bio load much better than a typcial HOB or canister style filter. Biological capacity is key with discus. Discus will get stressed very easily, so having a filter than will process all the ammonia and nitrite very efficiently is a good thing. Lets say that the tank will be fully planted, 10 fish in the tank and you are using a wet/dry filter. With that setup, I would recommend a 35-50% water change atleast once a week. More frequently if you plan on keeping more discus/other fish in the tank as well (due to increased bioload). Yes, discus can be very intolerant of less than ideal water quality. And do not get water quality and water clarity mixed up. I hear everyone saying that they havent done a water change in a month and their water quality is still very good. I call BS!! They're water isnt of very good quality...maybe good water clarity, but not good quality. There is a HUGE difference and dont let anyone try to tell you different. And with discus, it's all that more important. Also, pH stability is MUCH more important than the actual pH level itself. I dont care what the books say, or your LFS says to you regarding pH levels with discus...they will do perfectly fine in the pH that comes out of your tap (once aged/aerated and pH has settled of course). I know people who keep discus in a pH of 8.2 and they are breeding them!! Trying to keep the pH at like 6.5 or lower is very challenging at times and the fluctuation of the pH will stress the fish to no end and will eventually kill them. Dont worry about the pH. Just focus on warm water, frequent water changes and good stock to start off with (also very important...stay away from LFS discus...).
-Ryan
Orlando Discus