It's been a while since I thought about a stingray tank but let me see if I can remember. I was going to do Motoro which get 8-9 inches, they are 190 at petsolutions. Com but 150 right now, they need sand due to delicate skin, and temperamental to water conditions. Need soft water and I have very hard, and illegal to own in my state. 250 Gallon is a starting point due to size. My starting off price was around 2000 and that was to just the bair necessities to get tank running.