Need opinion on leaves curling and browning

Edges of leaves are yellowing and curling down and up
I am misting the tent because of the low humidity
but i can't spray the plants because two are autoflowers so my mh light is on 24hr and I don't want to burn them , I raise my light quite high and they are stretching but id rather that then to light Burn them I'm guessing it's just the low HR but PLEASE give me your opinion I really want to fix my girls , oh also I'm useing pro mix potting soil with some perlite and the general organics go box for nutes at they are on day 21!

I've never used GO, but that's for soil. You're using soilless, it's not biologically active.

How do you water? It looks like the wet pattern is irregular. Do you completely water with some runoff, and then let it dry very well (the weight of the container feels very light)? Or, are you adding a little water every day? (that's bad).

What kind of water do you use? If tap, what is the TDS/PPM?

I see what looks like a K problem around the edges of the leaves. That could be due to overwatering (not letting the soil dry). Could also be a mismatch between nutrients for soil and using a soilless medium (but, maybe people do that without problems. I don't know.). It could be Mg def. That could be from low ph too.

Clearer photos would help.

I use tap water and I haven't tested the ph but I have used it for other grows and it seems to be fine also I water every 2days a good water and the pots feel a lot lighter before I do so , also in the go box is a mg and calcium additive , I water so often because of low HR of 10on avg :/ I try to spray and cover the bottom of my tent with water but that's only helps for maybe a half HR! Also Thanks man

That photo is clearer, but without natural light I can't tell much. Looks like a ph problem. But, I can't tell. It doesn't look like what I saw in the first photo.

What is the TDS/PPM of your water?