Temperature issues


I likewise have a temp problem....my air is set to 77 at home....tank temp 84-86 alll the time....using ice cap 660 w/440 watts of mixed aktinic/aqua tank size is 120gl 48x24x24 and running a lil' giant external under tank w/ 2 802ph's in tank. I likewise cannot seem to keep the temp lower...My tank has been up for almost 8 weeks w/ lr, snails crabs 2 cleaner shrimps, a green starfish (forget his name) and one gold tail damsel. i raised the canopy up 4 inchs w/ tubberware cups, but to no avail....i guess i need at least to fans on my canopy.....skimmer is out of the question for now....I dont want to kill anything so i dont plan on adding any more fish etc as of yet........trying to make a plan (cooling).