I clean my own Perch, so I choose to keep only those over 8" to make the cleaning chore worthwhile. On the occasion I get a gut hooked perch, I will keep those 7 inchers. Just to much work filleting those little buggars for the couple bites you get. Also, I use small bottles from drinking water that I freeze and add to my minnow bucket. I can keep emerald shiners all day in my aerated bucket with ice bottles. On really hot days, I bring along an extra gallon of my well water from home so I can change out the water in the minnow bucket to help.