I set up my 135 gal tank over a week ago. I used the cildid sand that contains bacteria and have 2 eheim canister filters running with an underground jet system. I did use a carbon/ammonia absorber mix in one of my filters. I have 8 small fish in the tank for a week and all my levels ammonia nitrate and nitrite are 0. The test kit is brand new. I thought the ammonia levels began to rise within the first week. When should I expect the tank to start cycling? Do I have to wait until the nitrate is about 40 before adding more fish? Thanks in advance for your help.