Originally Posted by Mattyfelts
we need exact numbers, your good and our good could be very different. IMO
you shouldn't buy any fish you can permanently house. If it is dead, i would wait to try again until you have a 300+ gallon tank that could support him. Also your going to need WAY more live rock. about 1-1.5 lbs per gallon so probably another 70 if not more lbs. How are you filtering the tank and what are you using to test?
With all due respect, I think you are being a little overboard here. I've imported and hatched many cat shark eggs over the years and the pup, when hatched, is a small animal that does not need a tremendous amount of swimming space. In fact, most of the time I hatched them in 10 or 15 gal
tanks and didn;t house them in larger tanks until they got use to being fed. That small animal in such a large tank, as you suggested, has a greater chance of starving than surviving. (IME) If we were talking about larger cat sharks, I would agree with the size. But you also need to consider that some hobbyists want the experience of hatching the eggs and growing the animal for a bit with the full intention of rehoming the shark when it gets too large for their current tank(s) by either upsizing their own tank or finding someone with an appropriate sized tank. So to say you should only have an end sized tank for a beginning sized animal is a little much I think.
The only real issue here is water quality. If the water quality was bad, THAT is most likely why the egg died IF it died after purchase. Unfortunately, unless the egg was candled at the place of purchase, there is the possibility that the embryo was dead when purchased. That being said, yes, a little more exacting answers would help us and more education would help the OP.
Just my take on the matter.