Vaderbanger is basically encouraging you to deprive pleco's of proper food -- partially starve them -- in order to stunt their growth so they SEEM like a smaller tank will be adequate to fulfill their housing needs.
Small tanks do not have enough algae growth in most cases to support more than the tiniest of plecos. They MUST have additional food supplementation -- algae wafers, variety wafers, etc. -- in order to remain healthy and grow properly. Expecting them to just "graze" on bits and pieces of leftover food that other fish miss and the little bit of algae that is growing in a tank is a starvation diet for plecos.
Small tanks do not have enough algae growth in most cases to support more than the tiniest of plecos. They MUST have additional food supplementation -- algae wafers, variety wafers, etc. -- in order to remain healthy and grow properly. Expecting them to just "graze" on bits and pieces of leftover food that other fish miss and the little bit of algae that is growing in a tank is a starvation diet for plecos.