I believe it's 20 gallons. I know when I saw my first crawfish, I bolted over here and did a search, and that seemed to be the most common answer. Lots of crawfish on this forum, with a bit of search.
I honestly don't know, the type they sell in petstores, brown shell about 2", tons crammed in one tank . Not a blue crawfish. Sorry That's my goal to figure out the search tool by the end of the week.
Ok next time I go to the petstore which will be tomorow I'll have a good look at them and try to find a match, all they say there last time I was there was crawfish for .99$.