I beg to differ! Start with Panaque plecos as they are vegetable eaters,driftwood eaters, etc. I have 2 big watermelon plecos L330 in my ray tanks and they are a good tank mate. I have also seen flagtails go with rays also with no problems. I would go with the royals,watermelons or something that is big in the panaques so your rays don't munch on them. Not really a fan of the flagtails.