Best Water Coolers

It’s summer and I am having tons of trouble with the heat. I can’t afford AC and I am considering buying a swamp cooler.

I’ve got a few questions on em.

1. How will they affect my room humidity? I don’t know what it is now but I don’t want it to be too humid. If it’s possible I’d like to also point the fan at my computer to cool it a bit, but I’m worried about the humidity.

2. How much will they lower temps? I am planning to use water close to 0′C mixed with some ice to keep it real cool.

I have a 5 gallon and a 10 gallon fish aquariums and the temperatures on both at the upper limit (80-82 degrees). the thermastat in my apt. is always set about 74 degrees, so it never gets hot in my apt. I,ve went online trying to price water coolers but alls I see is coolers like you would see at a fish store (big/expensive). I bought a heater for not even $20, so surly I should be able to find something for about that price. can you tell me what to look for and where to go to get one, Or is there some way to keep the aquarium cooler without having to buy a cooler which would be safe for my fish?