greatwhitegoldfish wrote: Can you please reply without any "well your tank is to small."
Ok, no, because they are a shoaling fish... and... your tank holds about a tenth of the water required to keep a group successfully. And then there are the other requirements, like a substrate of mud, peace and quiet from tankmates, and a constant supply of live foods...
A Snow King in 20 gallons? Do you realise how big they get? (assuming it is one, which most aren't).