Brown spots on leaves.

[Hushpuppy]

That looks very typical to calcium deficiency, but phosphorous def and overfert can also look like that. I would say that you may have solved it by cutting back on the nutes.

I would recommend that you do not feed anymore than 800-900ppm and that is for some chow hounds that you want to get very big. Typical hybrid strains will not need more than 600-700ppm during veg. and less when the plants are younger.