i have half inch to 1 inch mexican beach pebbles as my substrate in my piranha tank. the thing is that food gets stuck under the rocks (so annoying!!) i have added slate to try and stop the food from falling. my question is would a pleco be ok with that kind of substrate. i need some solution and i know its a risk with the piranhas but alot of people say it can be done and thats a chance i need to try and take.. thanks.