Nitrogen deficiency? Lockout? Something else?

Hey all,

I've had a lot of trouble with my plants in the past, but just recently started getting what appears to be a big rash of N deficiency throughout my plants. My lower leaves are turning yellow/dying and newer growth has yellow/brown burns on the tips.

Last week I hit them with a heavy dose of veg formula (Fox Farm Grow Big). I am using the fox farm line of products (Grow Big, Big Bloom and Tiger Bloom).

I found out about three weeks ago that my tap water was at Ph 8 and I was not Ph adjusting at the time. I flushed with 6.5 water and have been Ph adjusting both waterings and feedings since.

Here is my form. Any help is greatly appreciated!!!

SOIL:

How long has this problem been going on? Two weeks, getting very bad in the past few days.

What STRAIN are you growing? Bagseed

What was the establishing technique? (seed or clone?)
Seed

What is the age of your plants?
4 months old, 4 weeks through flower

How long have they been in the soil mixture they are in now?
4 weeks

How Tall are the plants?
3 feet

What PHASE (seedling, vegetative or flower) are the plants in?
4 weeks through flower

What Technique are you using? (SOG, SCROG etc)
SOG-ish. Tying them down

What size pots are you using? (Include how many subjects to pot)
5 gallon

What substrate/medium are you using? What brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?)
Fox Farm soil with perlite mixed in, about 70/30 split soil/perlite

What Nutrient's are you using?
Fox Farm line

How much of each nutrient are you using with how much water? *Knowing the brand is very helpful*
Medium-heavy doses Fox Farm recommended (1-2 tablespoons per gallon)

How often are you feeding?
Every other watering, more often lately

If flowering, when did you switch over to using Bloom nutrients?
Three weeks ago (1 week into flower)

What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect)
I've mixed both veg and bloom without considering the order

What is the TDS/EC/PPM of your nutrients used?
Unknown

What is the pH of the "RUN-OFF"?
Unknown, last time I checked around 6.5-7

What method of pH test was administered? Using Strips? pH pen?
Liquid PH test with plastic tube

How often are you watering?
When the soil is very dry

When was your last feeding and how often are you feeding?
6 days ago with a very heavy feeding, feeding every other time with medium strength solution

What size bulb are you using?
250 W plus ~150 W Floros

What is the distance to the canopy?
1 foot

What is your RH Factor? (Relative Humidity)
Unknown, but lots of airflow

What is the canopy temperature?
Unknown. May be a bit hot, but nothing that doesn't make me feel pain when I have my hand there for 10 seconds

What is the Day/Night Temp? (Include fluctuation range)
Unknown

What is the current Air Flow? (cfm etc.)
190 CFM

Tell us about your ventilation, intake exhaust and when its running and not running ?
Tent setup in closet. Lots of room on sides and cracks of closet. Have small holes for intake from bottom of closed closet, exhaust at top with plenty of airflow. Two small fans in room

Is the fan blowing directly at plants?
Yes, at low speed, but yes

Is the grow substrate constantly wet or moist?
No

Is your water HARD or SOFT?
Unknown, PH is about 8.0

What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water?
PH adjusted tap water to 6.5

Are you using water from a water softener?
No

Has plant been recently pruned, cloned or pinched?
No

Have any pest chemicals been used? If so what and when?
None

Are plant's infected with pest's?
None

I would say N deficiency...I would also lower the pH of your feedings to around 5.8-6.0 and flush your soil. ;-)

Maybe sounds like even being over watered?

We really need a pic to decipher whether its a deficiency, lockout, or nute burn...

Here you go!

Definitely a nitrogen deficiency...bump up your nutes, water every 3-5 days - don't let your soil dry completely out. If you are comfortable with foliar feeding and have a good formula, I would suggest if - if not, don't worry about it. They will come back quickly.

Just hit them with a heavy feeding of N. I'll make sure they are better watered in the future. Thanks!!!

Yeah, it looks a lot like my plants did when they were first going the N route. I'll say you're do not look as bad as mine did when I first found out. I all happened so fast... take a look. This is an older picture but I thought it gets the point across quite nicely.




Since then I've been adding 1 Cup of fermented urine to up the N, it seems to be helping the new bud growth. It turned quite dark green almost black. It's a really need effect on the buds!

There are things here that just don't sound right. 4 weeks flowering in 5 gallon pots of FFOF and running out of N? Feeding large quantities of nutrients and getting burn and deficiency symptoms? Low powered lights and tall plants?

Your lower leaves aren't running out of N, the plant is moving the N out of them and allowing them to die and drop because they're simply not getting enough light energy on the leaves to produce chlorphyll via photosynthesis - that's why the plants dropping them.

Your brown tip burn marks on your newer leaves are indicating over-fertilisation, which is consistent with your feeding program - you're feeding too much too often and it sounds as though your watering is off as well - it seems far too frequent for those size pots and that light source.

It's not a ph issue, but dolomite lime mixed in at potting up time helps to buffer and stabilise ph, stopping it going over 7.0 which will help optimise nutrient uptake, but as I said, it's not a ph issue.

You've now flushed a lot of useful organic matter and wastes out of the rootzone when you didn't really need to - switching to plain water and allowing a little run off (a very mild gentle type of flush) would have been all that was required to remove any excess built up salts, because organic nutrients don't contain many.

My suggestion is to learn and understand how to water your plants correctly and when and at what levels of nutrient you need to feed at - it sounds to me like your plants didn't need any nutrient feeding yet and now you have to try and repair the damage of over-fertilsation. One of the most common faults among inexperienced growers.

Urine should be used carefully in flowering plants, and in any plants period. It's a great fertilizer, but it is an ammonia nitrogen source, and those types uptake into the roots aggressively. So if you give them too much you'll stunt your flowering.

tree&leaf said:

There are things here that just don't sound right. 4 weeks flowering in 5 gallon pots of FFOF and running out of N? Feeding large quantities of nutrients and getting burn and deficiency symptoms? Low powered lights and tall plants?

Your lower leaves aren't running out of N, the plant is moving the N out of them and allowing them to die and drop because they're simply not getting enough light energy on the leaves to produce chlorphyll via photosynthesis - that's why the plants dropping them.

Your brown tip burn marks on your newer leaves are indicating over-fertilisation, which is consistent with your feeding program - you're feeding too much too often and it sounds as though your watering is off as well - it seems far too frequent for those size pots and that light source.

It's not a ph issue, but dolomite lime mixed in at potting up time helps to buffer and stabilise ph, stopping it going over 7.0 which will help optimise nutrient uptake, but as I said, it's not a ph issue.

You've now flushed a lot of useful organic matter and wastes out of the rootzone when you didn't really need to - switching to plain water and allowing a little run off (a very mild gentle type of flush) would have been all that was required to remove any excess built up salts, because organic nutrients don't contain many.

My suggestion is to learn and understand how to water your plants correctly and when and at what levels of nutrient you need to feed at - it sounds to me like your plants didn't need any nutrient feeding yet and now you have to try and repair the damage of over-fertilsation. One of the most common faults among inexperienced growers.

Click to expand...

When I did flush it was mild as you described. I probably ran a half-gallon through each 5 gallon plant.

In any case, adding the extra N worked. I think you're right in that I flushed out the nutrients. It was in response to the low Ph. In any case, there's more N in there now and they seem to have bounced back.

Alright, i looked and the burns are indeed growing more frequent. I hit them with some fresh water. I adjusted/optimized the lighting today so hopefully things will work better on the down low.