First grow

Aaagghhh! Leaves are still turning yellow spreading from bottom to middle ,few brown spots too, cut lot of dead leaf last week but still yellowing this week. Soil Ph was bit high creeping over 7, now Ph'd the water to 6 to try lowering it a little, I upped nutrients last watering 2 days ago for a heavy feed according to the labels on bottles, I've given a light dose this morning as Im sure it's a nutrient deficiency? Giving each plant around 3/4 litre every other day now with or without nutes, think i overwatered last week or so giving them 1.2 litres each feed. Top of plants seem good but can't seem to stop the yellowing, one day they look like they're dying then they look good the next, also moved lights up to 3ft away from canopy today see if that helps. temps are good in tents, so frustrating when they looking ill 🤒. Think I'm doing everything right? Gonna leave them for day or two now to use up the nutes and see how they react, be plain water next feed. Hope they look better soon im waiting to start flowering but scared to change over while they not at their best.