Day 11 flowering with CFLs - Fan leaves look diseased

So everything has been great so far.
2 top 44 and 1 unknown sativa
~200 watts of CFL on 12/12
day 11 of flower
water every 3-4 days, till soil is bone dry
last nutes I gave were last week
unknown pH
soil mix - MG moisture control, vermiculite, peat moss, earthworm castings, sand, normal potting soil.

is this normal dying of fan leaves during flowering or a deficiency of some sort - i noticed the largest fan leaves turned yellow and spotted from one day to the next.

looks like mites to me.. look under your leaves

yellowing looks like nitrogen def and brown spots always thought they were start of nute burn but might be mites

i got a few leaves like dat and i aint got mites

unknown pH
soil mix - MG

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It looks like a pH issue. You need to know the pH of both the water you are feeding your plants with and the pH of the soil which you can get some indication of either by a soil pH tester or just pH testing the run off from your pot when you water.

water every 3-4 days, till soil is bone dry

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When youre in flower it pays not to do that. Keep up a regular watering schedule keeping the soil moist but not wet, and certainly not bone dry even for a short period of time.

I am assuming MG = Miracle Grow?

so update is:

no mites, double checked.
thanks for the advice on the watering, i won't let the soil go dry.
i use my fish tank pH tester to check the water i give the plants - its exactly 7.0.
MG is miracle grow.
I ended up watering them with a heavy dose of nutes, and the leaves responded well. no more dying leaves, so somthing was missing from their diet

Day 23 Flowering

On a good note:
the plants have stopped growing upwards and are now filling out, with buds developing.

On a bad note:
the leaves are starting to show signs of spotting again. The spots appear from one day to the next, then the leaves start to turn yellow and die. It is happening in lower leaves, and very slowly moving up to the middle leaves. The spotting looks like necrotic spots.

Specifics:
pH of water going in is 6.0 - i give miracle grow nutes every other watering. I water once every 3 days. soil is very well drained and airy. The temps are around 75 F and the humidity has been 65% which i know is high - i have a dehumidifier in there which doesn't help much. I don't think its mold or fungus because i see no signs of anything living on the soil or stems or leaves, just spots out of the blue.

is this some type of deficiency or strange nute burn?

Attached are new pics.

The first is a leaf in midstage death - yellowing but smaller spots.


The next is a leaf in late stage death - not as yellow but larger spots.


The last one has a backlight so you can see through the leaf, showing the small spots on a healthy leaf.

In soil you want your pH to be 6.5 else phosporous, calcium and magnesium will become unavailable to your plant.

so you think this is the problem?

with nutes the pH goes to 6.0
without nutes, plain tap water after sitting is 7.0

should i give them half nuted water every time, so the pH is 6.5?

If you can get some pH up that would be better or else half strength and since your feeding every other watering, try feeding every water. If you see nute burn then back off to every other.

But first things first youre going to need to flush your pot with pH balanced water till it runs 6.5 out the bottom. If you havent done this before heres a little vid I found that has someone doing just that.
http://www.ganjaguerrilla.net/calendar.html
Download the link that says, "PH & Flushing streaming video".

I'd suggest you flush it. It looks like nute burn.

Thanks guys - will flush and test the water out the bottom and see how things go...

smoothdemon said:

so you think this is the problem?

with nutes the pH goes to 6.0
without nutes, plain tap water after sitting is 7.0

should i give them half nuted water every time, so the pH is 6.5?

Click to expand...

The level of acidity between 7 and 6 is 100 times. Sometimes those spots on the leaves are an indicator that pH is swinging too far up and down.

After flush either try half feeding every time, or get some pH up and down and control your pH to 6.5, i.e. pH your tap water down to 6.5 on the straight water, and pH up your nute feed to 6.5

Thanks - I have the pH up and down products from my fish tank - I just haven't been very strict with pH i hope this works.

+rep

so my new problem is - the plants are too big to take out of my box...

I was thinking to put something UNDER them to catch the water...

HELP?

edit:
I thought about it and i cant flush them because they have time release nutes in the soil.
I ran water through them to test the pH coming out of the water - it is 7.0 on the dot.

well thats the prob. right there. a-re you mixing any nutes into the soil with your water? its nute burn

You would have thought though that 2 weeks into flower would be long enough for the slow release nutes that came in the soil to be used up already. Or is MG just a crap soil (dont have that brand in my country).

In the veg stage i had no nute burn using MG soil. and according to the MG site, the time release nutes last 1 month.

3 weeks ago I added fresh soil to the plants when i transplanted them, so in a week the nutes should be pretty much done.

Maybe its a combo of nute burn and bad pH monitoring on my part... I will see how my plants do the next few days and try a flush if i have to... but definitely will only water with 6.5 pH water - no nutes for the next week or so.

yeah definitely try with out nutes. you could easily be over feeding your ladies.
nute burn nute burn nute burn
post more pictures and updates

Update:

Today I watered with water only and molasses. ph 6.5.
It seems nute burn has been controlled because it isn't affecting any new leaves...

new problem:

relative humidity has been high lately because of the weather - 70% and up. So i have been battling humidity in my box - i have a small dehumidifier in the box, and have been running the heater in the house to suck moisture out. Humidity in the box got to as high as 80% !!!! - right now it is at 68% hopefully the weather turns for the better soon, i would hate to get bud rot.

No new photos tonight - too lazy - i'll try tomorrow