He is eating like a champ :) but she is loosing weight

The first part of this year I got a big beautiful male ball. I was told he was a picky eater. I had a heck of a time getting him to eat anything and he went months without a meal, and I was starting to worry really bad. Well I was told he like 2 small rats but would eat a med-large rat. Welllll, my idea of a small rat and the person I got him froms idea must have been totally different. LOL I finnally gave up breeding rats as he is the only one who (is said to) eat a rat and threw, my idea, of a tiny rat into his cage and BAM he ate that little guy before I could blink So a few days later I threw my second to last tiny rat in his cage and BAM again, gone in a heartbeat. Well, I thougt I might actually be on to something so I left him for 5 days and threw in my last tiny rat and again BAM. This boy is finnaly eating regular . I should have asked how big a "small" rat was. So my question is this how often should I feed him? He has gone about 4 months with only an occasional meal. I dont want to over feed him but he has actually gained weight on just 3 meal (he is now 1600g he was 1500g when I got him. He is also soaking in his water dish (swimming in it) for hours at a time. Is this normal? It has been HOT here. I am keeping the cage as cool as I can but the cool side gets to be about 80 deg(that is with a fan blowing in the cage) the hot side is about 100(that is with NO heat like I said it has been HOT) at night the cool side drops to about 68 deg and the hot side about 95. I don't have airconditioning. The humidity is about 40%.

My other bps are doing ok, with one exception. They are growing and I went back and looked at what they weighted when I got them and what they weigh now and I can see that all but one is gaining. One girl was about 300g and now weights about 400g ( I got her in jan of this year) the other one was, the other boy was 140g and is now 300g. The last girl was 580 and now is only 500g. She has basic the same conditions as the large male with the exception is she is not soaking in her water. She has not been eating very well (that is why she is loosing weight). Could it be the heat? Anything I can do to perk up her appitite? Once she killed the mouse and didnt eat him and once she killed a weanling rat and didnt eat. I have tried F/T both rat and mouse. What more can I do?

Thanks