In my uneducated option, I’d say to stay away from that with stingrays. When they drop the stinger it will only be a matter of time until it punctures the plastic I would imagine. However I have no experience with the tank or stingrays so take my opinion with a grain of salt.
I've had these 'ponds' before and had no issues with them. I set it up as a saltwater pond loaded with live rocks and ran the pond for 2 years or so. This is when the pond was first setup and the fish/groupers were first introduced.
Not really... there is too much that can't be seen with only top view. Best to be able to see how healthy/plump a ray is from the side instead of just the top.Would you recommend for rays?