Well I 20 long would be a lot better than tall, so you should be able to keep a few other dither fish in there. Pretty much you don't want them breeding right smack in the middle of the tank. In a 20 long they should be fine if they're kept in one corner doing their thing. I'd put the pot on one side with a stack of rocks on the other. The kribs will pick their spawning place and the rest can be with your plants and etc. Just don't put anything center that they can claim and spawn in. Goodluck