When I had an African cichlid tank I had about 180 lbs in a 90 gallon. If you go to Lowe's or home depot you can get Lighting Grid to put on the bottom of your tank to distribute the wait better. It is plastic grid that is 1/2" thick 1/2"X1/2" grid squares. Put that on the glass, rocks on it, then sand/substrate to cover it up.
Sent from my LG-P509 using MonsterAquariaNetwork App
Sent from my LG-P509 using MonsterAquariaNetwork App