Originally Posted by Kudaria
What test kit to you guys use to check the level of potassium in your tanks?
I have not found any good (reliable) potassium kits that are cheap. There are some expensive ones out there, but you probably don't want to spend the money.
As long as you are noticing potassium deficiencies, keep up with your dosing; I have not read of any ill effects with heavy potassium overdoses, and I believe Tom Barr has tested concentrations above 100 ppm.