Are you certain its the feeders doing it...what gph are you running and on what sized tank? List some more details...if your filtration is enough your water should not become cloudy. If its cloudy this means you're probably not pumping enough gph or you're overloading your tank. And if you think its the feeders you don't need a feeder tank...the toilet is ample enough if its really them causing the problems. Which do you care about more...the feeder or the piranha...I choose the piranha...get them out of there if they're the problem.
How many feeders do you add to your tank? It is usually a spike in ammonia levels that makes your water cloudy. Goldfish are known to cause amonia levels to go though the roof. Another reason I hate them.
I say take them out. Better to loose a few dollors on goldfish then much more on your p's.