I thought I would post an update on this tank. I've been running this tank for almost month now with the controller. So far so good I've been able to keep the ph 7.2 and I've reduced the light intensity by 30 percent. the temp is sitting at 29.5C. The plants are still showing good growth. The current tank inhabitants also show no change in behavior. I believe the conditions in this tank are as good as it's going to get for discus.
I am planning to add them to the tank soon.