I am treating BRS dry rock in lanthanum chloride to remove the phosphates before it goes in my DT. However, I don't have a good phosphate meter to see what's actually going on with the levels, I am winging it for now. From what I know only the Hanna meters are accurate. They are $50 and I only need to use it for a week or two until I can verify the phosphates are no longer leaching into the water. I was hoping I could borrow one for this process. Thanks everyone.