I need a nitrogen addition to this system as an adjustment. The algae eater has outgrown the tank and I'm intent on switching from the 29 gallon( 110 l) tank's current occupants into the much, much cooler looking television cabinet tank, and adding the retrofitted aerogarden to that tank. I think this is a better design approach, and I'm certain that the 20 gallon tank (76 l) could support and entire wall rack of retro-fitted aerogardens, producing more of the interior design ethic I'm interested in accomplishing and marketing. The pleco won't fit that design intent, it's two years old with me, and about 5" (12 cm) long. It's the largest of the tropicals in the tank.
I had 2 plecos in a tilapia tank at one stage, where they lived happily until the water temp got too low for them and I moved them into an aquarium. I intend putting them into my large research system as soon as I know it is ready.
Dan, I've had 2 plecos in my big tilapia tank for the past year or so and they've seemed pretty happy. You should be fine, but if you start looking for someone to adopt him bring him over when you come visit this week!