Ice packs to chill tank in summer?

[GoFish]

I guess I'll trial and error the ice packs in the next couple days, good idea using the fan on the controller but the only reason I haven't done that is it's based on evaporative cooling which will raise the humidity in the house. I live in a 1 floor house with literally zero air flow when the house is locked up, I don't even have a fan above the stove or in the bathroom.

There must be many variables to this as well, but is there an approx amount of additional top off water I could expect to use when running a fan 24 hours a day. Going camping next weekend for 4 days so will most likely be using a fan. Currently the tank in reference (45 gallons of water) uses a 5 gallon bucket of water every 5 days. So that's 1 gallon per day. If it raises my top-off water use by much I'll need a larger bucket