Quickly yellowing after possible over watering

you always should water till run off, collect it and throw out. i use simple car wash sponge, goes quickly. its coco based, run off more important than soil, proper watering, to saturate all pot without leaving empty/dry spots - is essential too ph you follow, so this is big win. you have to add very light dose of cal/mag in coco grows every second feed too, like 0.25-0.5 ml/l in veg should be ph 5.8-6.0, in flower 6.0-6.2 , many things would go outs. now i am certain you watered a bit wrong and they could be hungry. in soil I usually go for around 3-4 liters of water or food every 3-4 days, in coco same amount for 20 liters pot, with collecting excess run off out and cycle should be every two days. think at week 5-6 they will need even 5 liters to saturate and satisfy. girls drink best around second hour after lights on aka in the morning. divide all amount into 3-4 parts and water with interval of 5-10 min between each part. all should be diamond

Top soil is dry as of now; all pots are still slightly moist on the bottoms about 1/4 heaiver than empty. I have 2 ph meters and calibrate them weekly. They look underwatered? Should I water til run off and test that ph and EC? My guess at needing mag is off then? There is some redding/purple on leaf stems as well. I'll add a few more pics right now.