Hi. Through my kids, I entered the aquarium world 2 wks ago. My daughter started with a 5 gallon tank...then in less than 2 wks upgraded to a 12 gallon tank, and my son now has the 5 gallon. The 12g currently has 1 glofish and 1 cory cat...with plans to eventually add 4 more glofish. The 5g...