| | Re: Test kits: the good, bad and ugly
LaMotte makes great test kits. Pricey but way more accurate than most. I also find them hard to find.
I have a potassium kit by LaMotte. I like the Seachem kit as it has a reference solution.
I find it difficult to make reference solutions for PO4 as the amounts for 1 gallon are small. My digital scale does 0.00 but I don't trust anything in the hundredths.