My amonia level is still .50 ppm. No nitrites and no nitrates. 3 days ago I added a tablespoon of flake food but still no rise in amonia. said:
Your tank is still early in its cycle it sounds like. You have ammoina in the tank, theres no reason to add more. Give it time, and this ammonia will turn to Nitrite, then to nitrate. It can take some time. The first 2-3 weeks are usually the ammonia cycle going up then dropping off, then in the last week or so you will see your nitrite spike then drop quickly. At this point you should have 0 ammonia, 0 nitrite, and a little bit of nitrate.
I'd just be patient and leave it be. Other suggestions above are very good as well, such as some live sand from someone, or a piece of coctail shrimp or something. If it was mine I'd just let it be for a month though.