Kevin, I'm surprized nobodys said this yet, but I think 77 is a little low for a normal running temp. I usually keep mine at 79-81.5. Now with the warm weather it hits a high at about 84.5 every now and then and hasn't affected anything. I hav noticed it only is at that temp for about 1 hour though and drops back down. But if you look at some of Dr. Ron Shimeks articles, he reccommends to keep your normal tank temp at 82 to a lot of people.