Hello, I have a question about a recent upgrade I made. I have 55g saltwater tank that had a hang on bio wheel filter that sprung a leak. I went to PETCO and they recommended I upgrade to a canister filter(Cascade 1000). Anyway, I went to the local fish store today and told the guy I tossed my bio wheel for this canister filter. His jaw dropped and he said I probably lost most of my beneficial bacteria. I have live rock but he thinks that the wheel carried most of the bacteria and assured me the fish had about 10 days to live. He also said the canister filters would not sustain bacteria due to lack of oxygen in the canister. I panicked and bought a bottle of Live Nitrifying Bacteria as he said it would get me a couple of weeks to figure out how I will get a sump/refugium into my system. Is the sump nessessary? How will I know if the bacteria is enough on my live rock? Any signes before my fish die off?