BigEasy1
Well-Known Member
You need calcium.
I use Cal Mag every time and the rusty spots only start when the plants gets a little too tall and I'm out of head room. If the plants stays short I have nothing but perfectly green plants. I could maybe up the amount of CalMag I use but I'm not sure if that will help. I'm already using a teaspoon per every 2 liters of water which is about double the normal dosage.