Spots on leaves??

What is this from??
small yellow/light brown spots, only on one or two leaves per plant, and only on one 'segment' of the leaf.
does anyone know what could be causing this?
i have gone over all of my plants with a magnifying glass, and i do NOT have bugs.
growing indoors in soil <1000 watt>

Might be just a buildup of heat in your room, how is the venting?

Any chance you may have dribbled some nute/water solution on them where they could have sustained a few tiny burns? I've heard that a bead of water can possibly magnify the light enough to cause a burn, but I'm not sure about that from experience. I always avoid leaving any water drops on the top sides of leaves, especially where closest to the light source - just in case... Anyway, the spots appear similar to the burn left when a leaf touches one of my CFL lights.

It's a burn on your leaves. I have the same thing on one of my plants from when I watered it and didn't get all the water off the leaves. The water as said above acts like a magnifying glass and the result is a burn. Just try to make sure you give your plant a shake after watering or feeding.