I have two full grown adults in a 20g long. I just moved them into the 20L about 2 months ago and have been conditioning them with mostly grindal worms and some blood worms and frozen daphnia. Before moving them to the 20L they were in a heavily planted 55g with a bunch of other corys.
For some reason Sterbai are hard to come by around here so I only had two, but this weekend I was able to locate some more at ridiculous prices and purchased two more. They are now in QT, but I'm hoping that adding them to the 20L will increase the spawn or maybe even develop into a mated pair. I definitely have my eyes open for a couple more to get the school up to 6 corys at least.
Saturday morning I collected 8 more eggs off the glass and plants in the 20L. This was by far the pairs largest spawn. So far two have hatched and it looks like the other 6 are going to make it. So we will see....
I've got a group of Pandas that spawns all the time in their species tank, but they always lay the eggs in the flame moss and I never feel like pulling it out of the tank. Well about a month ago I found a little guy who somehow survived and I've been fattening him up ever since. He's grown tremendously and now swims with the school.