Several different symptoms, advice please

[Sideburnt]

Hi everyone, a shame my first post is about my sick lil'uns, but help would be great, I've read several FAQ and symptoms identifiers and my problem is I have several sometimes opposing symptoms.

What brand and type of soil?
CoCo fibre and absorbant gel crystals

Indoors or outdoors?
Indoors
What strain?
White Widow & Mama Mia
How old are the plants?
1 Month
What type of lights and how many watts?
200w CFL
How far from the lights?
Initaly 6" now more like 18"
What, how much and when was it fed? NPK?
Initial water used for compressed CoCo had Canna Coco nutrients added, 1 week ago I added nutes again
What is the medium/runoff pH?
7, I've just watered with Ph Down'ed water at 6
What are the temps and humidity in the room?
70 humidity about 50-60
What size pots?
3-4 L
Any bugs? Look real close.
No
Any other pertinent info?
Growing in an inside hydro setup, good airflow

These are my 4 plants, WW on the right, MM on the left


It looks like my Sativa WW are doing just fine a bit of yellowing, some light drying on the tips


My Indy's though are not fairing too well, on the front left, this is the sickest.
Leaves are yellowing and drying out(now a lot more dry than the photo, starting to brown), looking very wilted. Leaves bending down


My Indy on the top left is showing different symptoms, the tips of the leaves are yellowing but thats it, the leaves are curling upwards this time, but a healthier indy than its sister.


I have avoided watering in the last week, incase I was overwatering ( a litre over 4 plants maybe twice a week.

I've raised the light up to around 18"

I've Ph lowered some water this morning to 6 and watered after a week of not (see above)

I think I should flush, but Im not sure incase I've been overwatering or over feeding, or perhaps something else, my first grow so im still learning, help would be awesome as i think im going to lose my one of my indy's

Thanks in advance

[jmfe1]

I've never touched that kind of medium but you need those cfl's closer, probably about 3-4 in away. Also another couple cfl's would not hurt anything. And how much nutrient did you add?

[Sideburnt]

The grow medium is supposed to be very kind to MJ, with a perfect natural Ph, I did have my CFL very close to my plants, but obviously, with sick plants I was exploring every possible cause, such as heat burn

And hence I moved the CFL lamp further away.

My little Indy is looking very ill and wilted now, I'll try a nute flush tomorrow and hope I can reset everything.

Im really surprised at the resilience difference between Ind. and Sat. under the same conditions.

Any further advice and help would be excellent.

[Sideburnt]

Well I flushed my plants today, with ph adjusted water, I added some h202 too and some chlorine remover.

My sick Indy plant has now turned 2/3 yellow and some of the leaves are brown, the symptoms moved tot he new growth, and my other plants looked to be showing symptoms too, yellowing leaves, dry spots.

Seriously though, there's not a lot of advice floating around?, I'm thinking I've done the right thing, in effect resetting by flushing but id like some heads up in case things don't improve, perhaps this looks like nutrient deficiency to an expert eye.

Thanks

Oh and for the record my CFL is one of the large plug and grow variety, plenty of light for 4 plants.