i got a 280 (6'3'2't) with a 15" niger cat and a 5" irwini cat. its pretty empty. theres a 6" pair availible to me. how long would i get out of them before i give them to the zoo?
IMO with excellent filteration and WC, should be ok for a long, long time. Maybe life depending on the ray. The cats on the other hand...

You're good for several years and possibly a lifetime for the rays depending on the size the female gets. I have a 4 year old pair in a 5' x 3' 240 gallon and they are happily breeding! Male 11" and female 14".
