You can find some at a pet store in liquid form for all of these. The strips are fairly accurate for the nitrate and ammonia, but not so much for the pH or other things. Liquid is best for accuracy though. A company called Hagen makes some that are relatively cheap and come with enough testing liquid to last about 40-50 tests. Realistically you only should need to do one if you suspect a problem with your water. Hope this helps!
