Welcome to the forum, you have arrived at the correct spot to ask questions. IMO your water is fine for discus as long as you are not trying to breed them. If you cannot do at least 25 percent per day or 50 percent every other day water change, do youself a favor and give serious consideration to keeping Afican ciclids instead of discus. Lots of us use brute trash cans or 55 gallon drum and a pump.
I am sure you will get plenty of more feed back here. Good luck.
Ron