Dying plants in Autopot-like system
I am new to hydroponics; I am using the Smartgarden system from Futuregarden, which uses the SmartValve to regulate nutrient delivery to plants. I am growing in a mix of perlite and coco coir.
After a few weeks of good growth, some of my plants (thyme, cilantro, melon, rosemary) have leaves that are wilting and dying. The thyme is almost dead--its top leaves started wilting first, and now it is spreading to the rest of the plant. The other plants in the system (peppers, dill, basil) appear to be healthy.
Does anyone know what the cause could be? I am seeing some salt accumulation on the surface of the coco coir; perhaps I should reduce the nutrient concentration (I am using full-concentration right now)?
I do not think there is a mold or root rot problem, as I don't see or smell anything funky in the reservoir.
Thanks for any help you can provide.