What's the role of potassium?
my tank was woefully low on potassium... but since I added in, it's kinda cool to watch the nitrate level fall. I'm assuming phosphate is falling too. Without potassium, the nitrate & phosphate levels just stayed relatively the same.
I know CO2, and water is used to make sugar, and the rest is used to make protein for the plant but what's potassium for?