I am going to add four Discus to my new 75gallon tank today. It is about a month old and the plants are taking very well. Not a single fish lost so far either. My biggest concern is my ph of the tap water runs around 7.4 . My understanding is this is okay unless you are trying to breed them. I have been working the temp of the water up the past couple days. I am hoping 82 degrees will be happy for fish and plants. We will see,,,,I look forward to taking on a new challenge. Discus have been something I wanted to do since starting.