I don't test the water. I go by smell, clarity and how the bottom looks where all the waste collects.
The turtle clean I use once a week as it says on the bottle and it will tell you how much to put in every week. I also use the biotize and aquatize whenever I add water. So I use all of them together. And for exta water clarity I use Laguna Clear Fast, which works wonders!! I put a little in and tahdah in a few minutes instant clarity that lasts for weeks! So once it starts to get a bit cloudy for excess fish food (cause I do have fish in with my turtle) I just add that in and it works great!
