Need help... new to hobby have a Cat shark and sting ray tank

Jamie St.Thomas

New Member
I am new to this hobby. I bought a 400 gallon saltwater tank. I have a sump tank and a protein skimmer. I also bought 250 pounds of dry live rock and 160 pounds of live sand. I put two cat sharks and two sting rays in it. I cycled the tank for a month with some some damsels. My levels went high and came down so I was told my tank was good to go for the sharks and rays. Boy I was given some really bad advice. Everything was good for a week. Then my fish stoped eating. I checked my levels and everything was way high. I bought 20 pounds of ceramic rings, 70 pounds of live cured rock, and 2 buckets of matrix (the buckets are 4liters each). I also bought enough bio sipra to treat the tank aswell. My levels came down enough my fish are eating again but still a little on the high side. I have 3 marine pure blocks coming in the mail should be here on Sunday. Is there anything else i could do? Or is it just a wait and see and hope I don't lose any fish?


Staff member
No way to cycle a tank that size using tiny damsels for large fish who are going to produce large waste. Also, not a good idea to use live fish to cycle. Live sand and live rock is best way to cycle. It is wait and see at this point. What is the ammonia level?