i agree with kathy. honestly man, you know im not one to bust any balls when it comes to you because i like helping people out, but im not going to tell you NOT to do a seahorse tank, but maybe reconsidder to something else in a species tank only. they are not for a casual reefer. much experienced.
i did sea horses awhile back, 3-4 years ago. had about 2-3 years experience. i should not have done it because i was not experienced enough yet. but i did anyway. the tank was set up for a year before i even though about buying my first sea horse. i had it set up in my bio cube. i took the stock pump out and replaced it with a maxi jet 900. i then took the return line that enters the tank and put a 90 degree elbow on it. i then took a foot long 1/4 inch diameter pipe and drilled holes in it and capped it at the end so the flow was spread out very good, but very lightly flowing out so no current really in the tank. i had about 15 pounds of rock laying flat spread out everywhere, not stacked up. i then got alot of cularpa and different plants and spread it out everywhere. i also had about 5 gorgonian in there about a foot tall and 2 purple sea fans. after the tank was running for a year i took out the 3-4 fish in there and added a pair of tiger seahorses and a pair of black cow sea horses. they did great. had live birth in there once about half a year after they were in there from the blacks. sadly there was so many babies it distroyed the tank. all my water pars spiked and i ended up saving my 4 sea horses and a dozen or so babies and gave them away. that was the end of that. went to simple reef after words because it more fun and enjoyable.
but to answer your qustion. my tank is never under 77 and never over 79.5. currently at 78.6 in both my tanks.
and also, by the way, just so you know, i sent that heater i told you i would give you out today, hopefully you get it in a day or so...