MY 6 Girls are Sick... (PICS)

Hello to the readers of my thread... I have these 6 different plants.. got a variety pack of fem seeds... they are all about 4 1/2-5 1/2 weeks old.. They just started getting small spots on the leaves and are looking a lil sickly.. im not really sure whats wrong but I've posted pics and hopefully some one will know exactly what to do....

Here's what I'm running

Ebb n Flow- Waters every 3 hours for 30min
24 hr 250w HPS light
2 FL Grow Lights
Floor Fan on 24 7
PH is between 5-6.. depends on the day
Nutes are at about 900, Fox Farm Grow Big

Looks like those guys are praying for magnesium. Look up a magnesium def. https://www.rollitup.org/newbie-central/16464-nutrient-disorders-their-related-effects.html
I cant see the spots well though, maybe get some pics in flourescent lighting.

Epsom Salt will do the trick - buy it at any farmacy

You could definitely be over watering those babies.
They look over watered.
Ease up on the watering.

I agree on the overwatering...

would that explain the spots on the leaves???

I adjusted the water to every 6 hours for 30 minutes... so 4 times a day.. Heres a few more pics with adjusted lighting..

https://www.rollitup.org/marijuana-plant-problems/132382-deficency-nute-burn-diagnostic.html

2.http://www.icmag.com/ic/showthread.php?t=11688

3.http://www.weedbay.net/overgrow-thebook/default.htm

4.http://images.google.com/imgres?imgurl=http://www.gardenscure.com/420/attachments/plant-nursery/209849d1186314471-nursery-troubleshooting-guide-nutrient_chart.gif&imgrefurl=http://www.gardenscure.com/420/nursery-reference/105126-nursery-troubleshooting-guide.html&h=335&w=600&sz=32&hl=en&start=21&um=1&usg=__F3KMhnmZITGTZH2eDhbOvR_DScE=&tbnid=IEsbmNB-iJNiPM:&tbnh=75&tbnw=135&prev=/images?q=tomato+leaf+chlorosis+picture&um=1&hl=en&sa=X

That second set of pics has better colour.
I think that watering schedule sounds better, they should improve in colour and leaves should stop looking limp and curling under once the roots get over the moisture stress.
Those brown spots could well be a slight magnesium deficiency as 'lampshade' originally suggested. It's quite a common prob'.
Try some calmag or I think some guys use epsom salts.
You should see some instant results with that set up when you use it.
PH shouldn't get below 5.5 but i know it can be difficult to keep consistent with those sorts of set up.
Keep us posted with how things progress.