"They are prodigeous waste producers, and the fish just plain gets too big for the tank"
Like too much waste for my filter to handle? I always over-filter my tanks, so the 10gal would be running a bio-wheel mini rated for 20 gallons. I don't mind doing bi-weekly water changes. At least not on a tank that small.
As for his size, at the store right now he and his bros are about 3/4" long. they really are tiny little fellas. When he gets big enough that he won't fit in the 10gal anymore, I could just move hime into my 45gal. It's not overstocked, and by that time he'll be big enough that my catfish won't be able to eat him.
I was just wondering, because my buddie has a comon plecto and 2 tetras of some kind in a 5 gal. He's had them in there for about a year, and the plecto is just now getting too large for that tank. And all he's running is a UG filter in there.