Ammonia is not the same as ph. Ammonia is the amount of fish/food waste accumulating in your tank water. Ph is the acidity of your water. As your tank sets up (biological filter), ammonia turns to nitrites and then to nitrates. Partial water changes (pwc) remove nitrates. And the cycle goes on and on (ideally). Ph is the least of your concerns as long is it stays stable. In my experience, my tap water determines the ph, and I wouldn't do much to try and adjust it. Although ph is related to ammonia toxicity, ammonia levels are your biggest concern for weekly testing. Nitrites are a concern if you are having a problem (death), and nitrates are the end result of the process so just do a pwc every week. If you are on a budget, get the API liquid ammonia test until you can afford the master kit. Stay away from the strips. I am curious what kit you have that doesn't test ammonia and what it does test.