The 6-in-1 strips have their uses. I use them myself to get an idea of GH, KH, and pH - the latter when my API kit gives me wonky results. I do like the API kit better because it is more accurate. You can take a water sample to your LFS or box pet store and have it tested. Also, you can use Prime to detoxify ammonia, nitrite, and nitrate while your tank is cycling. I've done this too.