I have the ALK and PO4 checkers. I absolutely love the Alk checker. It is fast, easy, and accurate. The PO4 one is nice but I don't trust it 100%. In fact, I am yet to find a way to reliably test for PO4 that I like. That is just a really difficult parameter to test accurately.
I do have the red sea foundation kit as well and personally think all of those test are solid as well. Mg is a bit of a pain to do but it is accurate and you don't need to test it as often anyway.
I do have the red sea foundation kit as well and personally think all of those test are solid as well. Mg is a bit of a pain to do but it is accurate and you don't need to test it as often anyway.
