sting ray

[StevenSeas]

I honestly don't believe that a 125 is large enough for a ray, nor for that matter are 90% of standard run of the mill aquariums that aren't specially built. This is because most rays will get atleast 12 inches wide and in an 18 inch wide that means that it will only have 6 inches to move side to side. It most likely wont be healthy in this size tank granted it is 6 foot long, that doesnt negate the lack of lateral movement that these species love. They are more about surface area rather than volume so height doesnt really play a part at all.

If you do decide to go with a ray, choose the 125. Get a ton of filtration for it, great over sized protein skimmer, and a sump with tons of LR and macro. Also make sure current is moderate/strong, with good surface agitation, but not lanier, and that all inlets have diffused suction so it cant get sucked onto the current makers. Keep metal out of the tank no matter what as well as no stray current so employing a ground would be helpful, as they have receptors that receive electrical current and stray voltage can "drive them crazy."

For feeding make sure that the food you are feeding are varied and rarely live unless they are enriched. All frozen foods should be enriched with iodine/iodide. This is due to a large portion of the diet being crustaceans that are high in this, but when they are killed and frozen the iodine isnt kept. A lack of iodine in a rays diet will cause whats called a goiter, it is a mass that can get fairly large right after their mouth and will eventually inhibit their eating.

just my opinion mixed in with some research and experience