This is actually a question for my dad's tank...plants just seem unable to thrive there. It's a 72 gallon tank with about 6 discus. The temperature is at 80 degrees with a PH of 7.0...his tank used to be densely planted and doing very well when it was a community tank, and ever since he converted it to a discus tank all his plants have died, and nothing is able to grow, java ferns melt away..amazon swords turn brown...He was told by a LFS that no plants can live above 80 degrees F?? that seems off to me...I've seen alot of planted discus tanks...any ideas on why this is happening??