I wouldn't suggest the shrimp/fish food method to cycle. I've been reading lately that leaving that stuff to rot in your tank can introduce all kinds of fungal/parasitic stuff. Not worth the potential risk, IMHO.
I would just pick up some pure ammonia from the hardware store. Best and easiest way to go about a fishless cycle if you ask me.
Originally Posted by SolomonFinch
Oh...I am planning on using gravel from my cycled 10 gallon. Already running the filter in it to switch to new 10 gallon tank later. Will this work for bettas? They seem more sensitive than goldfish.
Also, should I leave the media in the new filter, or just the bio filter?
Yes, that should work just fine. ;)
As for media....I'd ditch anything with carbon and floss before bacteria colonizes on it and instead replace it with a nice wad of some plain ol' filter sponge. Carbon isn't necessary unless you're removing medications from your tank, and isn't active all that long anyway, and the floss on those cartridges breaks down and falls apart eventually where as sponge doesn't. Plus, sponge will provide you with a little more surface area for the BBs to grow and colonize.