Top new growth yellowish

Am in 2 weeks flower.unknown strain. 8 reveg and 10 clones. for the past week i notice top growth is yellowish green but bottom very green. also some top leaves are curling down. they are in 15l plastic bags. 100% perlite drip irrigation 4 times a day for 10mins. they are being fed 10.10.20 formula. ph 5.5-6.5

I sprayed epsom solution 3 times. they seem to catch up on green but not there yet.
But what about curling? any idea friends?

You need to take photos with the lights off, everything looks yellow. It's hard to tell what specific deficiency it is without the proper color tones.

Anyone?

Anyone on this? what ppm do you run?

you're over ferting.

Do i flush? or stop watering for 3 or 4 days? or both?

you could flush out several times and gradually start adding fert's back in.