If you get a Motoro. They can and will get big. Expect to have them for the next 20 years.. Most rays are a long term lifestyle. As long as you take care of them rt, feed and love them, they will grow and can live a long happy life.
A 125 gal tank is just that, a 125 gal tank. In any ray, bigger is better. My opinion and most on here agree. If you have a 210 gal tank, then get it set up and cycled and use it. If you are planning on getting on, then please make sure you do.
125 gal tank is not big enough in the long run for a ray, even a Retic Ray years down the road... (tea cup as its known is stores) but can work SHORT term. It, and I mean SHORT TERM, can even work for a Motoro ray. SHORT TERM.. sorry, I can not stress that enough. If you have the 210 tank, then using your 125 tank till you cycle your 210 is ok, but if its a dream to get a larger tank in the future, then Id say wait till you get the larger tank. Things happen and if later after you get the ray, you are not able to get the larger tank, then what do you do. Better to have now, then dream and hope. SO many people say they are going to get a larger tank, and we all say the larger the better. but we really dont know if they ever get the larger tank or not, so we always stress the larger tank is better and its better to get it now than hopfully later.
Its never personal with us except when it comes to the well-being of the ray.
Bigger is better.
Motoro in my opinion would be a good start. But make sure you can get it rt the first time and know it is safe and loved..
I would also let you know, even a 210 in time will not be big enough... In time. so as long as you have all the facts. thats whats best