It probably depends on where you are and how cool you keep your house. I'm out in the Palm Springs area, so it gets HOT. I decided that it would be less expensive, in the long run, to buy a chiller rather than to run the AC
low all day. I ended up with a used JBJ Artica 1/10 for $175 on Craigslist. Works great, water temp stays right where I want it. You can always try the fans. Much less expensive and I've heard it works well for some tanks.