a Fish In cycle can't stall out, you just have to monitor it a lot more closely and be prepared to say goodbye to a 30-dollar fish (Assuming clowns are about the same price for you as me) I'm not a fan of using chemicals in tanks. Not for algae, not for bacteria. And since all you need to start a bacteria cycle is a tank with circulating water in it, and a little flake fish food, or pellets, ground up as fine as you can so it disperses and decays in the water faster. I did a fish in cycle on my marine tank. best way to cycle a tank IMO.