Mystery Deficiency?

Hey guys, i currently have a 18 day old Northern Lights plant, she looks healthy to me, but the two lower leaves are yellow with a brown stain on each, this started appearing about a week ago. This morning when i looked in i noticed she now has this on two other leaves higher up. The pictures can explain this better than i can. Its strange because i am getting a ph of 6.3 run off after watering, and she was fed for the first time tonight using bio grow (1/4 dose) with the same ph run off.

I am using 3 x 45w cfls (6500k), soil wise im using westland multi-purpose (with added john innes), including hydroleca for drainage. There's an ambient temp of around 80 and humidity of 35.

I have been told she just needs fed, but i just want a second opinion before it gets worse .

If you already fed but just recently then wait.

Ok man cheers. Does it look like a lack of nutes to you?

It does look like hungry kinda, but little early IMO, but Harley is right, you won't see results immediately.

sound man, ill wait and see how she is at the end of the weekend.

Soil temp? And your humidity seems low.

Not so sure on my soil temp to be honest, but ill check that in future. Whats the best way to boost humidity?

If you don't have/ don't want to get a humidifier, some wet towels hung in front of your fan will work.
Some guys put bowls of water, but personally, I don't like standing water.
I really don't think your humidity is low enough to cause an issue at this point.

Way early for Nutes, but she would probably benefit from the N she could get from Cal / Mag

Thanks Bakatare, that sounds like a reallly smart idea. My current humidity is ok for when she starts flowering though yeah?

Psychild - I hope that feed that i gave her doesnt go too wrong then haha. I have epsom salts if thats any good? Only problem is i have my cfls on 24/7, is it ok to spray them under those lights without the plant being burnt? Also can you spray feed something like epsom salts like a day or two after feeding or will that cause a nute lockout?

Just an update on the humidity - I tried that towel trick and my rh is now 52

If I didn't know any better i'd say thats a minor fungal deal

Well I just checked her and it's defo spreading a lot quicker now, I know I only fed on Thursday night so if it is a deficiency when will it show signs of getting better?

These are the updated pictures of the other leaves affected, plus new healthy growth. If it is fungal how do i correct it?