I have posted recently about wanting to have guppies, platys, and cherry shrimp all in one tank. Originally I thought I would only be able to have a 10 gallon but I quickly found out that was not a good idea. I have decided on trying to get a 15 possibly 20 gallon tank. I still want guppies, mickey mouse platys, and cherry shrimp but I'm not sure if this will be enough room or how many of each I can have. Also what would be better on the bottom of the tank, rocks or gravel and what color. Thank you so much for your help.