What size chiller would you use on about 75g my temp goes up to 86 with the lights on?
Something to think about - if you ever plan on upgrading tanks, a 1/4 hp is going to limit you (that is unless you want to have to buy another chiller when you upgrade). We had the 1/3 hp on our 75G, and it works quite well on the 210G also.

W.