Coming up on week 5 and getting some burnt tips and curling

[hefflm]

Only 1/5 of my plants shows signs of distress. Having a hard time narrowing down the issue. They’ve lived a happy and healthy life thus far. Want to nip this issue in the bud so to speak. Haha. Pictures attached

growing in FF OF with 1/3 worm castings. Organic nutes. FF Tomato and Veggie, FF Cavern Culture, epsom salt, crab shell, and RO water.

5x5 tent, 2xSF4000 lights. Really good airflow. 75 degrees and 40-50% RH.

 

[hefflm]

Other plants on this post for comparison.

 

[Dopesmoka]

Other plants on this post for comparison.

The only thing I could think of is maybe raising your humidity, if your always at 75 degrees.

 

[hefflm]

That’s easy enough. I’ve been running the dehumidifier nonstop to keep it down. I’ll turn that bitch off for a bit. It gets real humid here at night so I thought it was necessary to prevent mold during flowering. I’ll set the threshold to 60%-65%

 

[pulpoinspace]

since everything else looks to be in order, the only thing im thinking is the lime in the soil couldve been washed out and its struggling to keep pH in balance. do you have the means to do a soil slurry test to check your pH?

otherwise i would suggest pH your solution to ~6.5-7 every time you water / feed.

 

[hefflm]

Ohhhh I’ve been waiting to test this thing out... good idea!

HI981030 GroLine Soil pH Tester

The HI981030 GroLine Soil pH Tester is designed for taking direct pH measurements in soil for environmental and agricultural testing.

www.hannainst.com

I’ll test the soil first thing in the AM.

 

[Dopesmoka]

That’s easy enough. I’ve been running the dehumidifier nonstop to keep it down. I’ll turn that bitch off for a bit. It gets real humid here at night so I thought it was necessary to prevent mold during flowering. I’ll set the threshold to 60%-65%

Yup I’m going threw the same situation because I dropped my humidity at night too low and now I got curled leaves and some burning going on

 

[ilovereggae]

they all honestly look a little hungry to me. you should be darker green than that at week 5. maybe the ones showing more distress just ran out of gas already? what size pots and type of container? I would try to top dress with some more ewc. maybe its lockout but I would bet they just need food.

 

[hefflm]

7gallon fabric pots.

I actually harvested my own worm castings for the first time two days ago! I spread a healthy amount of them on top right after harvest and watered it in. The bagged worm castings I used when making the soil didn’t have any smell. This stuff though, my god. A few of my worms ended up in the soil, but I don’t think they’ll do any harm. Or survive for very long?

I’ll give these ladies a few days before I decide to add anything else. In the interim I’ll check the pH and raise the humidity a bit.

 

[Chemdog1989]

No it’s not your humidity lol
those girls are hungry. Or you have some sort of ph issue.
ilovereggie is right.

 

[ilovereggae]

I would also consider trying Recharge or something like Dr Jim Chicken Soup for Soil. depending on how much microbes your own ewc has going it may be enough, but it can't hurt to add more, plus the molasses in there gives the microbes some food. When I was using FFOF it made a big difference by helping maintain good soil life then ph didnt matter so much and plants were way happier overall. I used Recharge 1x per week from when I did my preflower transplant, up til week 6.

 

[Dopesmoka]

No it’s not your humidity lol
those girls are hungry. Or you have some sort of ph issue.
ilovereggie is right.

So are you saying high temp and low humidity does nothing to a plant ?

 

[pulpoinspace]

So are you saying high temp and low humidity does nothing to a plant ?

it does but 75f is not high and 40RH is not low.

 

[Dopesmoka]

it does but 75f is not high and 40RH is not low.

every vpd chart I seen indicates that a plant doesn't transpire properly that way so something must be off

 

[Dopesmoka]

but what do I know i'm just a dope smoker

 

[pulpoinspace]

every vpd chart I seen indicates that a plant doesn't transpire properly that way so something must be off

VPD depends on two temperatures. air temp and leaf temp. Most charts use a difference of 1-2 degrees for air and leaf but it actually varies a lot based on your light source, ambient temps, and exhaust etc. unless you have an infrared thermometer and you're plugging values for actual leaf and air i would disregard any VPD chart.

I wouldn't worry bout low humidity in general for that matter, unless it gets down to single digits. I have never seen low humidity negatively effect my plants. High humidity on the other hand can ruin a whole crop in flower very quickly. So I usually try to keep humidity under 50% for the final month or so.

 

[hefflm]

I used some Recharge last week. Used some FF Big Bloom two weeks ago. Homemade Worm Castings about 3 days ago now. I’ve been trying to keep the feeding light and all ORMI certified. I do have some already cooked subcool supersoil I can top dress with. That’ll give em a bit of everything. Never used super soil, had it set aside for my next grow. Any thoughts/recommendations on that? Trying to keep this grow as close to organic as possible...

 

[Rurumo]

Did you get a chance to test the soil PH yet?

 

[hefflm]

Nah, I’ll go down in a few hours when the lights turn on. I’m cynical about those green headlamps. haha

 

[hefflm]

Ok, so 4/5 of my plants’ have a soil pH range of 6.8-7.2. The one with lime green leaves, burnt tips, and curling read 6.81. Using a high quality Hanna meter freshly calibrated. Interestingly, the last plant had a soil pH of 7.8, but it looks healthy. Pictures attached.

So I’m guessing they’re just getting hungry. It does kind of look like nitrogen deficiency. But we are half way through flower, so I wouldn’t think to feed them N.

i can feed them subcool super soil by top dressing; that should give them a bit of everything. I also have a bag of FF Tomato and Veggie (5-7-3) and cavern culture (1-12-0). Don’t think the CC would do them any good, as they don’t look all that P deficient.

just kicking around ideas. Thoughts?