leaf yellowing (pic)

I found some leaf damage on my plants today so i sprayed the whole crop with pest off.

AS i was doing this i foung a couple of leafs that had yellowed on one plant
This was the worst one.

ec is at 1.7 and ph is 5.3

Check your meter, that looks like low ph to me. I've gotten that look before in my dwc when the res gets low the tds shoots up and the ph drops. Calibrate meter and adjust to 5.8 is my suggestion.

Thanks ill give it ago

just got some ph 7.0 solution and my pen was out. reading 6.6

so that would have made my solution higher than 5.3 so any other reasons for the yellowing.


i have mixed more water now and am getting a true reading of 6.0 to be on the safe side.