What kind of meter would I use for stray voltage? I have one tank that's been struggling for months. All my parameters are in check and consistent. I've done numerous in tank KFC treatments. I just can't figure this one out. I've done out of tank concentrated KFC dips at 5-hour intervals for 5 days at a time. This is driving me absolutely nuts! Haven't changed the lighting or anything. Tank is 6 years old. I know this is a loaded question but what could possibly be causing me this tank to slowly fail?