Thanks for the feedback Zandor.

Checked for signs of spider mites - I'm pretty sure thats not it. Plus my soil plants in the same grow box were unaffected, which leads me to believe it was most likely in the water.

I'm using a chemical PH tester so its not 100% accurate, but I'm confident its between 5.5 - 6.2. I check it every morning and its been pretty consistent.

It must have been a change in the environment/water that day.

The good thing is in the past 3 or so days I have not seen any more signs of this problem and the plant has increased in size by about 25%.:dance:

Fade :thumbsup: