Help with 1st coco grow please

Ok you have vegged under 200w flourescent and now under 600w HPS, that's one hell of a difference in light intensity and you'll probably find that the plants are just adjusting to a different light spectrum, they could also be suffering from some kind of bug in the root system although it is very rare growing in coco. They may also be adjusting to a much higher level of UV because I noticed yellow around the edges of the leaves, back the HPS light off to 2 - 3 ft for a few days then gradually move down to normal 12inches from the canopy, for a couple of days also get your water at 5.7, I know this is not much difference but I feed twice a week at this pH as Mn (manganese) is not available to the plant at 5.8. It's all about balance, hope this helps

id go with maxpesh about the light, i got some similar, just changed from 250 cfl to a 400 hps in a small cab .

The 600 is about 2' above the plants right now. I started off high and plan to move it down in a couple of days as they acclimate to the higher watt light. I could be wrong being new to this but i believe the light is far enough away from the plants. The plants have been looking like this for a few weeks. Even when i had them under the T5s in veg. Any other suggestions that you may have would be appreciated. Thank you

Any other suggestions

Epsom Salt

Epson Salt?