New to growing and need some help....

Hello,
I have been reading on the site for a wile, but this is my first post.

i started my grow a month ago and all was well untill about a week ago.

Here is my grow set up

2 One Gal Pots
Foxfarms Happy Frog Soil
Foxfarms Nutes
bagseed under 9 23watt 6500k cfls 18/6 light cycle

temps are 80-85f during the day 70-75f at night
RH is at 42-50% in the day 30% at night

I ran water for the first 2 weeks. I then feed the plants 2 feedings of 1/2 strength FF growbig. Around a week ago the plants stopped growing and started getting dark spots on the lower fan leaves. The spots only appear on the old growth. I checked the run off PH it was at 5.5. I flushed with PH adjusted water about a week ago and still no signs of improvement. I think its a MG deff. but im unsure Please HELP!!!!!!!!

Here is them as of a hour ago....

bump....in need of some help!!!

Kind of looks like this to me:
Magnesium
Chlorophyll has the same structure as Hemoglobin, except that it has a magnesium atom in place of the Iron atom. Chlorophyll is how plants make sugars to feed the process of building ATP through the Krebs cycle.



A magnesium deficient plant is identified by intervenial chlorosis, necrosis, and eventually a lockout of plant nutrients. The problems starts at the bottom of the plants and works it?s way up.



These images depict different stages and signs of a magnesium deficiency. The first picture is a Mg deficient plant in flower, and the second two are of the leaves to show what I mean by Intervenial Chlorosis.



Treating with an Epsom salts mix will clear this right up.

Just stir about a tablespoon of epson salt per gallon in your watering next time and only give it a little of that water at a time and observe the effect.

thats what i was thinking it was too...i'll water today with epsom salt and see what happens.....any other ideas?

Here is a good link for identifing plant problems.

it looks like your geowing in soil and your ph should be 6.5 not 5.5 that would lock out plenty of nutes i would get that fixed b4 adding anything

after flushing my ph is at 6.2-6.5. I watered them with the epsom salt mixture today so hopefully they will start to turn around. Thanks everyone for the advice and support.

i pulled them and started over...https://www.rollitup.org/grow-journals/163418-grow-2-white-dwarf.html check it out