I would not feed them untill they recover, it is more than likely that the feeders is what caused the problem, and do not wory they can go a loooooooooooooooooooong time without eating before you have to worry (mine went 7 months when I was trying to get mine to stop eating live feeders, they are still alive and kicking with zero health problems).
When they do recover and since you have not feed them, I would work on geting them to eat prepared foods like pellets or frozen fish from the grocery store, much cheaper in the long run as well. There are a few threads posted here as how to get Gars eating foods other than live, but the biggest issue is feeders, unless raised by you, are not a good idea, not to mention they can not compare to pellet foods for nutrition.