Brown Spots 4th Week Flower?

[erwinsweeney]

These are Ak-48 in 4th week flower. Growing in 2.5 gallon soil pots indoors. Given PH 6.5 filtered tap water, used PH pen. Using Fox Farms Trio, about 1/2 strength once or twice a week. 250 watt 2700k cfl bulb placed about 3"-4" from canopy, and 120 watt LED light used for supplemental lighting. This problem started about 3-4 days ago, and is growing. Spotting is now showing even on tiny leaves on main bud cola as well.

 

[HippyInEngland]

Hello Erwinsweeney

What is your RH?

What air intake and out take have you got?

It looks like you have a mould growing.

Can you put a link in to what your PH pen is?

eace:

 

[erwinsweeney]

Hello Erwinsweeney

What is your RH?

What air intake and out take have you got?

It looks like you have a mould growing.

Can you put a link in to what your PH pen is?

eace:

Thank you for responding HIE. I don't know the RH? I have one 80CFM fan blowin in and one 80CFM fan pulling through a carbon filter and blowing out of the tent. I took a couple pics of my PH pen. I calibrated it 3 days ago with 6.86 calibrating solution. I took a few pics of another newer leaf, and tried to get more of a close up so you can get maybe a better look. If it's mold forming on the leaves, do I chop the buds before it spreads to them?

 

[zipflip]

could this be it by chance?
got this scanned from my horticulture bible

 

[erwinsweeney]

could this be it by chance?
got this scanned from my horticulture bible

Thank you for responding Zip. It sure seems plausible. I read that whole page, and it does sound a lot like what I'm seeing.

 

[HippyInEngland]

Great post Zip

If it is P then its a PH issue, the chart shows your PH is out.

You say your PH using that pen and it is 6.5, have you checked the PH of the run off?

eace:

 

[erwinsweeney]

Great post Zip

If it is P then its a PH issue, the chart shows your PH is out.

You say your PH using that pen and it is 6.5, have you checked the PH of the run off?

eace:

I have not tested the PH of the runoff. I will test that today when I water. Thank you very much for reply.

 

[zipflip]

thanks for that chart too HIE
i remember seein it somewhere before and went lookin for it one day to keep a copy of it for my reference along wit all my other e-notes i keep of everythin. now i got it. thanks man.

i'll tell ya wat erwin, if ya got say 30-40$ to spend. i suggest the marijuana horticulture bible if your just still a beginner grower especially. it has come to my aid many many times so far. and is well worth the money imo.
im sure a guy can find it cheaper somewhere even. just do some googlin aroud maybe for it.
thats where i got that info from. i just scanned it onto my puter and voila.

 

[erwinsweeney]

Great post Zip

If it is P then its a PH issue, the chart shows your PH is out.

You say your PH using that pen and it is 6.5, have you checked the PH of the run off?

eace:

I have just run 1.5 liters of PH 6.5 water through it, tested the runoff, and it shows PH 6.4

 

[erwinsweeney]

thanks for that chart too HIE
i remember seein it somewhere before and went lookin for it one day to keep a copy of it for my reference along wit all my other e-notes i keep of everythin. now i got it. thanks man.

i'll tell ya wat erwin, if ya got say 30-40$ to spend. i suggest the marijuana horticulture bible if your just still a beginner grower especially. it has come to my aid many many times so far. and is well worth the money imo.
im sure a guy can find it cheaper somewhere even. just do some googlin aroud maybe for it.
thats where i got that info from. i just scanned it onto my puter and voila.

I will follow your suggestion with gratitude. Thank you.

 

[zipflip]

ya welcome man.

 

[MindzEye]

Hey Erwin, I had a PH pen just like the one you are using, I didnt like it, it has no temp compensation, and I had to calibrate it every time I used it, I was going through so much calibration solution that I started to think, with all the money Im spending on solution I can buy a better PH meter...

Also do you keep the probe moist? Have you let it dry out at all? I also noticed you said you are feeding nutes 1/2 strength, by 4th week of flower (actually sooner) you should be at full strength nutes...

 

[erwinsweeney]

Hey Erwin, I had a PH pen just like the one you are using, I didnt like it, it has no temp compensation, and I had to calibrate it every time I used it, I was going through so much calibration solution that I started to think, with all the money Im spending on solution I can buy a better PH meter...

Also do you keep the probe moist? Have you let it dry out at all? I also noticed you said you are feeding nutes 1/2 strength, by 4th week of flower (actually sooner) you should be at full strength nutes...

Thank you for responding. I do not keep the probe moist. I use it to test water and nutrient PH, then I rinse it off, shake it dry, and return the protective cap, then put it back into the plastic snap case. Is there something different that you recommend? Also, what type of PH pen specifically do you recommend/use?

 

[MindzEye]

Thank you for responding. I do not keep the probe moist. I use it to test water and nutrient PH, then I rinse it off, shake it dry, and return the protective cap, then put it back into the plastic snap case. Is there something different that you recommend? Also, what type of PH pen specifically do you recommend/use?

With digital ph meters you should fould a small piece of a paper towel and put it inside the cap and keep the paper towel moist.. If a probe dries out it will ruin the ph meter....

The ph pen that I use was an awesome buy for the money, I had to calibrate it when I got it and have cheked the calibration several times and I havnt had to make any adjustments... Here is the pen link
hXXp://www.scalediscounters.com/shop/product_info.php?cPath=4&products_id=315