Should I get the Phosphurous Checker?

[tytown]

Agree on the Elos PO4 kit, that thing is a total waste of money.
So Wheelman and Craig, what are some typical values your phosphorus checker reads? And what do you expect it to read when you test?
Running GFO I would hope to see 10 and below but going by their rated accuracy there's no way I guy can even rely on that.
Just trying to gauge peoples phosphates and their expected reading from their ULR phos checker....
Thanks for all the replys so far