ElNinoanswered grow question 4 years ago Hi,
What you see here is already older. If this would not get more you can ignore it.
I think you maybe give too few nutrients. But it's difficult because I don't know the soil and your EC values.
If you wanna be on the safe side give one-day EC 0.9-1.0. Afterwards let the soil dry out for one day.
When you start again watering with nutrients you should see that the plants get darker after feeding.
Does not look like pests but just check with a magnifying glass.
hope it helps
hf&gl