Sorry, my camera blows and I can't focus properly on them.

So you think the minerals could be building up from the water? I really can't say if I'm overwatering or not. The leaves aren't droopy or anything. I basically just water with about 10-25 mL twice a day. At that point the soil is dry to very dry on the surface. I usually water just after the lights come on and just before they go off.

Here's the mineral content printed on the label of my water (per 100 ml):
Sodium 0.88 mg
Calcium 0.84 mg
Magnesium 0.19 mg
Potassium 0.06 mg

It's 28.8 mg/L which is considered "Moderately Soft."