What is this?

Not sure what this is. It onset very quickly. First signs was two nights ago then today it's really bad. It's 5'x5' room with 1000w HPS. Temps high 78F low 67F for today. Averages that just about every day. I maintain humidity with a 9 disc pond fogger as my normal humidity is about 20-30%. I maintain about 45-55% RH. They are in 3 gallons watering with cal mag and jacks 20-20-20 about to switch to 10-30-20.

These are on day 15 of flower come this Saturday. Plants vegged under two foot two tube t8 fixtures. Everything was lush and green when placed into flower.

Have you re-potted recently? Just wonder if your roots were damaged. Also bumping. My first thought, without looking for a leaf chart is phos def.

I also wanted to bump ya.

I wonder if the lights may be a prob.

Wish I could help more than just bumpin ya.

Try checking out this thread while you wait.
https://www.rollitup.org/t/have-a-plant-problem-check-here-first.559517/#post-7948303

20-20-20 ouch,,,little high on the NPK don't you think?

Any way that's P&K showing to much. One of the most common problems in flower.
What are you in? Soil, Coco? Could be the begining of a lock if your doing Coco. That would be a contributing factor.

The addition of extra P&K is more suited to the start of week 6 and used only once in that high a concentration 10-30-20.

Minor up swing in P&K at flip. Almost dbl it at week 4 and a single big blast a week 6 would work.

Look at the NPK of Dyna Grow and use that as a guideline if need be. That will give you a starting point and plenty of room to learn and experiment.

Your plants will finish out ok. The overall quality will be effected, but not so as you won't like it! You would like it BETTER if it reached it's potential.

Interesting so too much P and K...

Not sure how to feed with Jacks at all then. These were popped from seed Feb 5th. I've fertilized them three times since Feb 5th each time with 1/4 teaspoon of 20-20-20 or about 1 gram of 20-20-20. Each fertilization was spaced by a few regular waterings of just pH'd water. Which is on the low side of others that I've observed feeding with 1/4 to 1/2 teaspoon every watering.

Could this be caused due to not over fertilization of P and K but of a pH swing in the soil?

Which Dyna-Gro product are you speaking of Dr. Who? I went to their website and found that they have quite a few to choose from.

HumbleNMotivated said:

Interesting so too much P and K...

Not sure how to feed with Jacks at all then. These were popped from seed Feb 5th. I've fertilized them three times since Feb 5th each time with 1/4 teaspoon of 20-20-20 or about 1 gram of 20-20-20. Each fertilization was spaced by a few regular waterings of just pH'd water. Which is on the low side of others that I've observed feeding with 1/4 to 1/2 teaspoon every watering.

Could this be caused due to not over fertilization of P and K but of a pH swing in the soil?

Which Dyna-Gro product are you speaking of Dr. Who? I went to their website and found that they have quite a few to choose from.

Click to expand...

Just keep cutting the dosage back. Jack's, Peterson's, MG, they work, but they aren't optimal at suggested use.

Rodger that. Gonna test the ph of my runoff next time I water as well just to be sure. Will step back on fert and see how it goes.

Thanks fellas.

HumbleNMotivated said:

Interesting so too much P and K...

Not sure how to feed with Jacks at all then. These were popped from seed Feb 5th. I've fertilized them three times since Feb 5th each time with 1/4 teaspoon of 20-20-20 or about 1 gram of 20-20-20. Each fertilization was spaced by a few regular waterings of just pH'd water. Which is on the low side of others that I've observed feeding with 1/4 to 1/2 teaspoon every watering.

Could this be caused due to not over fertilization of P and K but of a pH swing in the soil?

Which Dyna-Gro product are you speaking of Dr. Who? I went to their website and found that they have quite a few to choose from.

Click to expand...

For the Dyna
Grow 7-9-5
Bloom 3-12-6

You see here the RATIO relationship between the N-P-K......With the Jacks, it's 20-20-20. No mater how you cut it down, That npk ratio relationship is out of whack for the plant your growing. Thus you have an imbalance that has lead to a tox condition.

Abiqua is right. It will work but not as well as more exact nutrients at the proper npk ratio's.

Now then, as for the Dyna (and other more proportional feeds). There are those who never switch to bloom feeds and do GREAT.....There are those who start bloom feeds at the start of week 4 of bloom (when the stretch slows way down and the bulking of the flowers begin) and do GREAT. There are those who begin bloom foods at the flip and do Great.
The key here is that the one's who do GREAT have time under their belts at growing, know what to expect and know what the plant is doing by the way she looks (they "talk" to us). This will only come with time. Be patient. I don't want to get into flip spiking or 6 week spikes right now. Simply get a few grows under your belt and as you'll get comfortable, you'll try new things on your own time.

Now then, let me address pH in soil. ( I see no pH problems being expressed by your plant)
When you pH the run off. You only get the pH of the run off, not the pH of the soil!
SOIL SELF pH'S !!!! (If taken care of properly)
Good soil mix's contain Dolomite lime and/or oyster shell to help control pH swings and add Cal. Soil pH goes like this. You water and the pH swings one way. As the soil dries out, it swings BACK the other way.
The living bio's in soil work in regulating pH for the plants specific needs! So then, that means that the use of Living bio's/like in "Zyme's" or AACT tea's and many other supplements will go a L-O-N-G way in keeping your soil/plant healthy and the pH controlled (I haven't pH'ed my soils in years).

I hope this was information well received. I hope you now understand some things a bit better.

May you go forth and grow,,,learning something every grow, until you simply do the same thing over and over again.

Good Luck and feel free to ask questions