Ok just got my first and ONLY Pleco. It's a Royal, and yes, even this little 3" guy already is pooping up a storm. Right now I have him on a thin layer of white gravel, since white just brings out the "Turds" what bottom substrate do you guys recomend? Right now he's in a 29Gal and once he's big enough he'll go in the 90. But intill then which I suspect will be a year what is the prefered bottom substraite?