Do I need a Chiller to raise SPS corals?

[ted]

I have been doing saltwater aquarium for 4 months now and I have a 100gal running 72 cree Leds, 1200gph return pump, full length overflow skimming box, 2s Ecotech Mp10's, Octopus needlewheel skimmer & 18w UV light and want to know if I need to get a Chiller to raise soft corals.
My temp during the day is 81 and at night 80 so my swing is small.
My friend keeps his tank at 78 and keeps Zoa's, stars & Anenomes and tells me I need a chiller.
I got some local Zoa's(I live in Hawaii) and they seem to be doing ok.
I also bought more online and they died(not sure if they acclimated well).
My system has zero levels of the Nitrogen cycle I get ocean water from local fishery and I dose Kalkwasser with top off RO water.

See my tank here:
http://s169.photobucket.com/albums/u232/chatoyants/?action=view&current=20120901181823.mp4

Any help appreciated.

 

[crister13]

Your temp is fine. The flow is what I would be concerned with. Maybe add 2 more powerheads.

 

[ted]

My tank was custom made so its 52" x 25" x 18" Im running 2x Ecotech Mp10's and have a Blueline T4 return pump at 1225gph. I did consider adding 2 more powerhead to the back but though it might be overkill. Since I am a beginner I will add them since I have 2 actually laying around. Thanx for input

 

[crister13]

Usually people shoot for around 50x overturn. As long as your close to that you should be good. I just said that because sps love flow.

 

[ted]

After adding 2 more powerheads(Koralia) in the back my temp rose 2 degrees.
I could get another Ecotech. . .

 

[crister13]

So your at 83? As long as its stable I wouldn't think if that as a problem. Try
Turning your heater down? I don't even run a heater.