Good advice so far! I've used chiller for the last 15 years. +1 on oversizing the unit.
It's the best insurance you can buy especially if you stock sensitive animals. I've always read that temps under 80 promote a more stable metabolism for corals and fish.
My soft corals thrived when temps where 76-78F. But whatever you set you temp at, a 2 degree swing seems to be really beneficial for you tank in multiple ways.
The JBJ actica chillers are nice, and they have a decent warranty service. My only advice is to oversize the unit, and get a chiller with a built in probe. That will keep it from running, if the feed pump shuts off.
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