Plant is dying! don't know why! please help!

I need some help with my plants. I have been in veg. for about 2 months now (from seed) and everything has been going great until about a week ago when i noticed a few leaves on the bottom had turned brown, dried up and died. The second I touched them, they broke apart into a powder and fell off. I am growing in a completely sealed 2'x4'x6' chamber with intake and filtered exhaust. i am growing under 2 48" dual lamp flouro's and 2 cfls (inbetween the flouro's) using miracle grow soil and miracle grow azelea 30-10-10 water soluable fert. They recieve 200ml of water every day. Since I noticed this problem I have switched to straight water but the problem has barely slowed down. They seem to be dying from the bottom up but several leaves on top have begun to develop dark spots. inclosed are 7 pictures. these plants have been trimmed duing their growth to allow for more branches and smaller leaves as can be seen in the photos. Thank you to everyone who replies!!!

whats your temps at?...looks a bit like a heat problem

oh...also whats your soil PH?

soil is approx 6.5. never far off from that. Temps are 78-82 degrees and humidity is around 50%. this varies a little during the day. lights are 18 on, 6 off.

more details plz. nutes watering schedule temps humidity etc get more info on here. looks like a ph or feed problem to me if the bottom leaves are yellowing first it could be lack of nitrogen with the plant sacrificing its oldest leaves to grow new ones
ripz

also, the leaves have somewhat of a papery texture. before this, they were a luscious green. i have a "no pest" strip hanging in the room, above the lights and i have not used any fungicides or pesticides.

plants are given 200ml of water every day. before, they were being given 30-10-10 nutes and in a soil with a 24 nitrogen. temps are 78-82 degrees F. Humidity is approx 50%. Lights are on 18/6 schedule. plants are watered once daily, usually in the afternoon.

lower the ph....for sure...put some coffee grounds in the soil...they have loads of nitrogen and will lower the ph

you want the ph around 5.5...

do you think, with the nutes and soil ive been using, that there is any deficiency in these plants? also, should i go back to using the nutes at full strength or half or keep with straight water for now?

how much water you giving them daily? what size pots? could be a bit of overwatering

dinkydigger said:

you want the ph around 5.5...

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ph in soil should be ph 6.5, 5.5 is for hydro dude

They are getting 200 ML of water a day. PH is right around 6.5. I'm using 10 inch pots.

also, should i include a humidifier in my room? I had one before and turned it on for an hour every 6 hours, starting when the lights came on.

have you checked to see if they are rootbound

humidity should be cool at 50%

no, the i havent checked but a few weeks ago some of the roots were showing through the top of the soil. they didnt appear to be then because the roots were out over 4 inches from the stem. i dont know about underneath.

I dont believe they are bound up. I have transplanted twice and have seen the root system expand into the new area around the transplanted part. Ill check when the lights come back on but im willing to bet that Im dealing with another problem.

I'm doing a scrog and my undergrowth fan leafs die off like this, which is caused by poor air flow and poor light exposure. I would certainly add a oscillating fan! Your leafs should always be moving in the wind.
Obviously make sure you do not have a def. with the leafs looking neon green like this. Did you do color correction on these pics?

Good luck,
Unity

kschurtz said:

do you think, with the nutes and soil ive been using, that there is any deficiency in these plants? also, should i go back to using the nutes at full strength or half or keep with straight water for now?

Click to expand...

I had the same probleme you have.Miracle grow is probably the worst soil or perlite you can use.You need to rinse all your plants,trust me if you don't,your girls will just die.Don't give them so much nutrients,some strains can take it more than others,btw what strain is it?
You may have to transplant your girls in different pots with different soil.I know it seems like a lot of work,but after you've been vegging for 3 months anything to save your crop will do.