I have been using this kit since i started testing for potassium levels and went to order a new on this morning only to find out that everyone everywhere is out of stock. Does anyone know if the Salifert potassium test kit has been discontinued? If so what does everyone use, Elos, Red Sea, KZ, Fauna Marin, others?? I can tell if my K+ gets low from my coral color but i am a nerd and like to track levels for dosing adjustments. Thanks for your feedback.