I decided to get a master test kit, and went with the "tetra test laborette" (whihc didnt have a no3 test, so i had to buy that seperate). It was 20 bucks and works just fine, but most of the tests require the use of 2 or 3 liquids, and letting it sit for 10-20 minutes. the no3 test even has zinc powder you have to add. I guess this is why dip-stick tests are so expensive. Anyway, are all master test kits like this, or are there any better/easier ones?