Hmm i didnt think about rays, but know you all got me thinking. The dimensions are 84x36x30. I havent really thought about breeding fish either what to do? I originally planned all big fish but now im thinking mixing both big and small. My idea is to use big rocks and make caves for small fish to hide and hopefully breed while some monsters cruise the open water. Imo that would look awesome. Im not sure what i would use for my small fish as my knowledge of small fish is limited.