Fast Buds mix (2nd grow)

Hey, thanks for the replies. Still having the same issue this morning. I have been waiting for the top of the coco to be lighter coloured and moist but not wet for the first inch of it. Before watering again which is about 1.5days so far but due to growth is around every day now. The EC (I measure in ppm) was 100 higher for the AK when I measured yesterday. I’m abit worried it’s stopped up taking now as it’s getting lighter in colour. I have moved the lights a few inches higher today to see if that has an effect. If not I will go back to watering issues being the cause and do the advised 3 instalments. So frustrating as it’s been a great grow so far and so much work to get the set up dialled in as it is. Thanks all and will keep you updated.

Checked the roots yesterday, no smell, run off ph was 6.2 so no issue there. Yup, intake brings in outside air constantly at a 20% fan usage minimum have a dual controller. Exhausting via filter. 2 fans moving air inside. Humidifier you can see on the floor in the pics maintains 50-55%. Temps are around 25c. I just dont understand what it can be, same set up, same nutes, using ph perfect so no ph issue. It just suddenly came on a few days ago.

How is the airflow in your tent. Do u have an exhaust?