Ohh, here's the big tip........STOP OVERFEEDING!!!!!!
I understand you were on vacation, but for how long? How'd it get overfed while you were gone?
Most fish are good for short periods of time with no extra feeding as there should be stuff in an already established tank that they can scavange. If it was a friend or loved one then you need a new tank sitter. Try a club member that you trust as they are experianced. If it was from an outomatic feeder, most of them are crap. However there are some good ones out there that let you portion the food how you want.
Also, I agree with Jay24k, there is only so much you can do. However ther's only so much your critters can do. So when all is said and done, you need to rid the tank of as much as "you" can.