Interesting, I've never heard that they need at least 10 gallons. Of course any fish would be happy with as much water as possible, and I think the 1/2 gallon set ups are too small, but I've read that 1-2 gallons and up are pretty good. They live in puddles in the wild, so I figured a couple of gallons would be good! I constantly check the water quality, and he seems very happy, and active, building bubble nests etc....