| | Re: Test kits: the good, bad and ugly
As many will say, you get what you pay for. Test strips are frown upon because all you get is a range.
A good test kit will give you numbers. But then, some of them are open to the users perception.
I read an article years ago, that stated that test kits are most accurate at the middle range.
When I got into the fresh water hobby, I started out with the "Nutrafin" test kits and was satisfied. But I started to have doubts and purchased a more expensive kits from the "Hach" company. When I tested Nutrafin NO3 and their PO4 kits against the more expensive Hach kits, they both gave nearly the same results. This speaks well for the Nutrafin product line of tests.
Now the Nutrafin line of kits cost anywhere from $12.00 to a bit higher I believe. I believe you will do well with the Nutrafin test kits.
Now I only know of one manufacturer that offers a kit for testing fresh water potassium and it is pricey.
The LaMotte company has this kit and it is around $60.00 plus shipping I believe.
But all is not lost on that parameter. The online companies that sell chemicals to hobbiest's such as nitrate, phosphate etc also includes potassium in their mixes. So it depends whether you need a test kit for potassium.