i have two 6-7 inch armatus right now in my tank and i have a bad alagea prob would it be okay to add a four inch royal pleco to the tank becuase i heard they could suck slime coat of fish but i also have 4 large sds in the tank but if the royal is well fed on alagea,driftwood and cucumber will it be okay,also my armatus amazingly ignore all the other fish in the tank except themselves but they do keep the others in check for example my sds dont fight anymore with them in there