Low or ultra low range?

[Scottsquatch]

I am about to order some Hannah checkers in preparation for my tank getting wet. I was wondering which phosphorus checker I need. Is it the low range or ultra low range? Or is it both? If both which one would I likely need first? Thanks.

 

[JMetaxas]

I just bought one, and got the ULR. My goal is phosphate within the range of this model.

 

[Greenstreet.1]

I have both of them but mainly use the ULR I like that it test to a lower range.

 

[Scottsquatch]

Thanks guys.