Should I get the Phosphurous Checker?

[lastlight]

The lowest reading I've gotten with mine is 0.02 but I've often got 0.04.

And thx Adam when can I expect your order? Kids are wondering how many more units they have to build tonight before I give them water and rest.

[MitchM]

I also use the ULR checker but I don't use it for accurate numbers, only trends.
I use a target of 10ppb though to adjust my Foz Down dosing.
I also take the appearance of the tank to tell me what's what.