We are setting up a brand new 250 gallon aquarium. We can put water in it tommorrow. I am getting driven crazy here because the guy at the pet store said to use Cycle, it is a great product, it will help the Nirogen cycle along and make the transition easier for your fish, he said he was going to give us some gunk from the tanks in the store to help get the process along too, so we could bring our fish home this weekend. GREAT YEA!!!! RIGHT? Well not the built the aquarium said do not use Cycle it is crap and can actually kill the bacteria you want in the aquarium gravel. He said do not bring the fish home, put the three bala sharks in there and that is it let the amonia go up up up up and then when the amonia drops add the other fish. Also do not mess with water changes, leave it alone Ok I have other aquariums and I have been very successful using cycle at the beginning and then every week thereafter. I do a 25% water change after 4 days, after 8 days and then every week thereafter, that gets me through the 30 day period and I water change once a month after that. This has worked very well for me, so it is what I want to do this time. I don't know what the right thing to do is, I don't want to lose any fish but I want my fish home, they have been paid for for two months now. HELP!!!!