It seems that as soon as the leaves get to about an inch, the spotting starts on the leaf. It's only been a few days since I changed the res/put in the calmag, so I have to see wether it's helping. This is a DWC system so it's constantly in water. The plants aren't that small anymore. At this point they're about 9-10" tall.

The water temps do get to about 77 before lights out, though. This should be fixed by the time I go to 12/12 (if I go to 12/12) due to the glass shield on the 400HPS reflector and the HPS causes less heat anyway.

As I said, I did have an algae problem. I guess light did get into the water somehow and hopefully it is fixed now. Maybe the algae wasn't letting the nutes get into the roots?