unknown,
well discus are fragile and sensitive is some aspects, but to say they are that way towards just water conditions is only part of the pie. In fact Discus can be kept using a variety of water conditions if acclimation is followed through properly, and the water quality (nitrates, nitrites, etc) is kept in check using regular water changes. The ideal
ph value for Discus is about 6.0-6.8 but I have heard of fish being kept at 7.0-7.5 .
Water changes play an important role in keeping these fish, and several times weekly to daily water changes are really a must for several reasons. In addition to that Discus are very succeptable to several aquarium related ailments - Hexamita being one of the most common. In some aspects though Discus are hardier than other fish so its kind of a trade off in some areas.
I would recommend testing your water, researching, researching some more, talking to breeders and PM'ing Brain NY who is an advisor here at AA. He knows a great deal about keeping and breeding these marvelous animals and is very willing to share his vast assortment of knowladge.
In my opinion the only thing Discus are very sensitive to are bad husbandry techniques and overly aggresive tank mates.