Can't seem to beat this issue, noob desperate for help

Here is my setup, hopefully i remembered everything.

Cabinet:
4'H X 3'W X 2'D

Lights:
It is a CFL (75W, 28W,28W,28W,28W). All on a 12/12 cycle

Airflow:
I have a 4" passive air intake, with a 4" output and a 135CFM fan.There is an 8" fan inside that blows directly on the plant.

Soil:
Using Happy Frog Soil (ph at around ~6.8 )

Watering:
I water every 3-4 days depending on the dryness of the plant. I alternate water, water, water w/ nutes. Water usually ends up around 6.2-6.5 so that runoff tests in the 6.5 range.

Temps:
Throughout the day temps range from 72-81F

Pruning:
I am constantly pruning leaves that are damaged or dying.

Plant Type:
Unknown, bag seed. Current height about 14 inches in 2gal pot (cannot really get a bigger pot in my cabinet.

Issue:
You can see in the image attached that I am getting spotting in the middle and burn edges. This continues until the whole leave dies and shrivels. Also note that the stem is brown as well. I have moved the lights changed the speed of the fans, a few weeks ago I even flushed... no avail it still is all crazy.

new foliage shows no signs of damage until they have aged and developed. I notice that the stems of those leaves have a brown like tinge to them as well. It feels like every other day I have to chop leaves of this plant to allow for new foliage to grow in healthy but the cycle keeps repeating itself.

It's not the lights proximity, and I don't believe its an airflow issue. The PH seems to be in the range of expectable. So there must be some sort of mineral deficieny? or something? i'm desperate to get through my first grow regardless of results, just so I can plan better for my next one. Any help in diagnosing the plant is greatly appreciated.

Hopefully I have provided enough info, and thank you in advanced for your assistance.

Well you gave really good info and a good pic but no info on NUTES

and what the pic shows is phosphorus def

What nutes are you using?

Flora Nova Grow and Bloom for the different phases. My water starts off at 15ppm and I add until it hits 225-250ppm with the nutes. I can't believe I forgot to add that I was trying to be so thorough.

riddleme said:

Well you gave really good info and a good pic but no info on NUTES

and what the pic shows is phosphorus def

Click to expand...

I looked in the trouble shooting guide/posts and that was one of my guesses, but it didn't say how to resolve it??

If you are waiting for the pots to be light before watering again then at least the roots will be happy. 250ppm in bloom is probably under feeding by a long stretch. Assuming you are about week 4 or later of bloom, at around week 4 plants begin to demand a serious amount of food as they switch into the last gasp phase of trying to reproduce. I would raise the ppm on your next feed to 850, then the following week up to 1000, then by week 6-7 you want to be at 1200ppm to give it the full strength it needs. Of course these are just arbitrary values, your eyes need to be the real guide as to whether these levels are over feeding or not.

Lastly, there is a lot of opinion around about plucking off dying leaves. Me I leave them on until they pretty much fall off, that way causing less stress to the plant. In the end flowering a plant is not a beauty contest and dried dying leaves are part and parcel of the phase the plants are ending with.

Jonus said:

If you are waiting for the pots to be light before watering again then at least the roots will be happy. 250ppm in bloom is probably under feeding by a long stretch. Assuming you are about week 4 or later of bloom, at around week 4 plants begin to demand a serious amount of food as they switch into the last gasp phase of trying to reproduce. I would raise the ppm on your next feed to 850, then the following week up to 1000, then by week 6-7 you want to be at 1200ppm to give it the full strength it needs. Of course these are just arbitrary values, your eyes need to be the real guide as to whether these levels are over feeding or not.

Lastly, there is a lot of opinion around about plucking off dying leaves. Me I leave them on until they pretty much fall off, that way causing less stress to the plant. In the end flowering a plant is not a beauty contest and dried dying leaves are part and parcel of the phase the plants are ending with.

Click to expand...

I just watered last night, but was think of doing some supplemental foliar feeding today just to be safe. I am at the end of week 1 for flowering, and plan to move to 500ppm by end of week 2, 750 w3, 1000w4, etc on that same scale.

i wouldnt foliar feed right now if was u....

PK foods have a nasty habit of burning!

up the ppm to around 800 like someone suggested, and next time amend the soild with bnemeal before you start. the bonemeal gives enough PK to keep your plants from starving and rusting between feedings.....
just my .02

IAm5toned said:

i wouldnt foliar feed right now if was u....

PK foods have a nasty habit of burning!

up the ppm to around 800 like someone suggested, and next time amend the soild with bnemeal before you start. the bonemeal gives enough PK to keep your plants from starving and rusting between feedings.....
just my .02

Click to expand...

The thought I had was a light misting on the leaves before the lights kick back in would allow the leaves to soak up the PK to prevent further damage. About an hour before the lights go back in I'll lightly mist the leaves again with plain water to prevent burn. I also cranked up the circulation fan to help dry that stuff before the light kicks on and gets it hot enough to burn.

I think I am going to stop cutting leaves and wait till they wilt, the only reason I will remove is if it is blocking light from other branches, etc. I need to stop the stress on this plant, its stressed already knowing she'll be smoked some day

Next Time I think I'm going hydro, lots more local support in the area for me to do so, and seems easier to adjust, just more cost. But regardless thanks for your input I'll update to let you know

As an FYI for future readers, This indeed was a phosphorus deficiency, I added some 0-10-10 mix at about 200ppm in a foliar fashion about 3 hours before the lights kicked on and increased fan speed to help absorb and dry. 1 hour before lights went on I misted the leaves again with plain RO water, to help rinse salts and anything else that may cause burning. Within 24 hours the leaves have a richer green color and some of the yellowing leaves reversed, and others have shown no further damage. Thanks for all those that contributed. I will be using the 0-10-10 in my feeding cycle, to help prevent this from occurring again.