yellowing to soon?

28 days in to flower, yellowing to soon i think

Could be anything. Nutes, air, ph, co2 etc. need more info

I recently had this issue and it was too low of ph. I'm using tupur which is a coco mix and my plants started yellowing and I check run off after I fed the girls and run off was 4.0 or lower. Easy enough to correct, so I would suggest checking ph.

They look nice to me but I'm a noob, only had 2 successful grows so far. I would check my ph and maybe hold off of nutes for a feeding but I don't know much about what you've got going on. And I said, I'm still learning myself. I second guess everything I do to mine. Hope it evens out

Thanks you guys,was one of the first things I checked. Run off is 6.5-6.8 in soil, no sign on older growth , never had issues with this grow really. not tell now. I've had other strains go early but not this early. This is a 8 week strain

Soil FFOF 3gl smart pot. Flora Nova Bloom 1/2 strength every third watering under 2x600 hps about 14 inches away. Always 15% or so runoff