You should look at the link that rwaterman posted. it has all the info you need right there. A 125 might be suitable for the smallest species but the bigger the better.
:iagree:Wow...ummmm...not sure really what to say here...but...that's some pretty bogus info. If you haven't already done so...I would highly recommend you go over to ]V[onsterfishkeepers.com. Ask the folks over there. Many ray owners.
And yes...you don't need a kiddy pool to keep them, just that alot of ray owners use them as they have an excellent foot print.
Scratch the 120 completely, entirely...it's a joke...a.k.a don't go there and don't do that to the ray. Bare minimum foot print for a ray tank should be 6x2x2. This is for the reticulated ray (so called teacup). Even better would be 6x3x2. As mentioned, most ray owners will either use a kiddie pool or build a shallow pond structure.
Yes it could survive in a tank that small but we could survive living in a box. IMO a 125 is to small and i would not be happy keeping a ray in one.