Album with imgur pics below in post. White spots on fan leaves day 24 They are under 2X600w hps 12/12. Temps between 23c-27c Have one oscillating fan And a big ass outtake fan with temp control and coal filter. This is day 24. The white spots on the leaves have been there for a while and are more present on some plants than others. In my next watering i will give them some water and calcium. What are the spots? Does anyone know? Album 5 pics : http://imgur.com/a/CHGmT#bQAieto
Rub a leaf and make sure it doesn't come off on your fingers. If it does, that's mold. If not, its probably a slight cal deficiency.
Looks like thrip damage to me. Look around real good, top and bottom of leaves. They're not really big, about a millimeter. Here's some pictures to give you an idea of what you're looking for. There are something like 5000 different species, so they may not look exactly like the ones here... http://mrec.ifas.ufl.edu/lso/thripslinks.htm If you do have thrips, they can easily be gotten rid of with Spinosad. Apply liberally to the tops and bottoms of leaves every three days, for four applications.