Hey guys. This isn't strictly about aquarium plants but I didnt know where else to post this. This came up in my alevel biology class today. The teacher said that too much potassium was bad for plants and it would suffer from it. I didn't quite understand this, seeing as we overdose our plants, and surely the amount of nutrients taken up by the plant would depend on the other limiting factors, most importantly light and CO2. If these weren't high enough to demand all of the potassium then how could the plant take up too much for it to cause a negative effect. She then answered that the potassium would be taken up by active transport and so the plant wouldn't be able to stop the uptake of potassium. I'm well confused.. can anyone shed any light on this?