I thought my qt was cycled, had put sponges in reef tank to seed, but 3 days after putting the Hippo in, the ammonia read at .25. Even with 50-60% water changes daily, it never went down. I want to get a small yellow tang in 2 weeks. I have heard to put fresh shrimp in the tank to rot and cause the cycle. What is your advice, how long will it take, and what amounts of whatever you suggest do I use. The tank is 20 gal with an Aquaclear trickle filter with (2) sponge. I also have a Maxijet 600 I can add if you think it is necassary. Thanks in advance, Dawn.