I also live in Texas, the warmer part, and I have been successful using fans over the sump to get my water temp down to 74 degrees from 78. My apartment is at about 74 degrees. Thanks Nancy for the suggestion! Target has small fans with clips on clearance for about 5 dollars, and we have 3 of them blowing across our sump. Muuuuch cheaper than a chiller. Now I just need an automatic top off, so I can keep up with the evaporation.
Good luck!
Shannen