Yellow marbling

[] [ ] Hey guys, so this is my first grow plants are under 400w hps in veg for 4 weeks. I have started getting leaf tip curl and a general yellowing of bottom leaves.
Soil ph 6.5 run off ph 6.8 started correcting for a nitrogen deficiency about 7 days ago have also addes some epsom salts as it was looking like a magnesium deficiency.
As i said this is my first grow and havnt had any advice only went off what i researched. Here are some pics any advice would be much appreciated

First it's heat stress and not magnesium deficiency. Careful with nitrogen. It's early for any deficiency. Forget runoff pH unless you're just looking for something to do. Do not overwater.

^ heat, and possibly not enough N...not M.......don't dump a lot of N on it at once, up it a little at a time......
and i agree, this isn't hydro, run off ph is useless to you, just something to confuse issues with.....if you put it in right, it doesn't matter what it comes out at.....

Thanks for the replies guys temps are 26c lights on and 18c lights off. Humidity is between 45-60% constant. How much of an issue is this ? and any tips on rectifying heat stress

those temps sound good, and so does the rh....i'd just feed them more, and make sure your ph meter is accurate. as long as you're feeding them in the right range, you should be good, so just up your feed rate for now, and see how they respond.

Roger A. Shrubber said:

those temps sound good, and so does the rh....i'd just feed them more, and make sure your ph meter is accurate. as long as you're feeding them in the right range, you should be good, so just up your feed rate for now, and see how they respond.

Click to expand...

Ok thanks, i also raised my light a little and adjusted my circulation fan, hopefully they perk up a bit i have another two like this and two others which are in pretty good shape apart from slight yellowing bottom leaves. Thanks for the info dude