Well, I've only been leaving my zucchini in the pleco tank for about 12 hours. When you use as much zucchini as I do, you try to keep the mess to a minimum. Now mind you, I have 11 growing bristlenose in there and I use almost a whole zucchini each time! They don't eat it all so last night after I removed what the plecos hadn't eaten, I trimmed a piece and put that in the discus tank for the 2 otos in there. I'll see if it looks like it's been eaten at all by the otos after work today. And I'll also try a piece in the sids tank where I have several otos.