Another concern I have is that on my older plant, the leaves are all curling up into "hot dog buns". Very peculiar. After some reading, I saw that it might be because they are lacking water, but I water them plenty. I'm wondering if it's because the leave are drying out, even though there's enough water in the soil. I have a fan blowing out the side (it's not blowing directly on the plants, but there is a breeze going over the leaves). Could this cause the leaves to be doing this?

God, I wish I could post pictures so people could see what I mean.