Leaves drooping and curling, really need some advice…

[Olezhkakot]

I have 4 plants in 80 80 growbox, ~18 days old (flipped to 12/12 5 days ago) with spiderfarmer SE3000 300 watt lamp, hanging about 15 inches away, currently on ~70% power(maybe it was a bit too much) temperature is about 26-30C(77-86F) day and 20C(68F)at night, constant humidity about 50% the plants are - apple blossom/hella jelly by humboldt, dosidos by barneys and lemon picon purple city all growing in 1.5gallon fabric pots in soil medium (Biobizz LightMix with extra 20% perlite)

I was expecting this to be the perfect grow, and really tried not to overwater it - for the first 5 days I was giving them about 50-100ml per day, then I progressed to 250ml every 2days. There was I day, when I think I accidentally watered them 2 days in a row(because I wanted to quickly give them nutes, cause they seemed a little yellowish), but the amount was the same - about 250 ml, mixed with half-strength AN sensi grow AB, and on the other day I found that all plants except apple blossom were droopy. As the amount of water still wasnt a lot I was confused, because the soil were never soakingly wet. Today it’s been about 3 days since I last watered it, soil now is not an inch dry, but half an inch for sure - I thought it should get better by that time - but I think they even look worse. Apple Blossom(lower left) been not showing any problems, Hella Jelly (top right) is not showing any progress, DosiDos(lower right) became a bit more droopy and curly, Lemon picon(top left)is somewhere in between.

My general question - if it’s overwatering, how soon plants usually recover in given conditions? I’m concerned accidentally underwater it as well, because if the droopy leaves persist even when soil is really dry - it feels like I have to water them anyways.

Also I know, that all watering guidlines put a big emphasis on the run off - which I never had during that grow, as the water also brings oxygen to the plants… maybe that’s the cause as well?

I think about waiting for 1 more day(soil will surely be dry an inch deep) and giving them enough water to drain through, but im not sure its a right idea,when the plant is already looking overwatered?

Or could it be the light that causing the problem, because the leaves are curly as well?

Will be very thankful for the help, as it’s the best seeds I could barely ever get and I don’t want them to turn into another shitty grow…

 

[ArtfulCodger]

I grow in soil and water to 10% run-off, only when pots are very light. Over-watering has to do primarily with how often you water, not how much water you give. I don't know what media you're in. If that's soil, plants that small in pots that big might go a week or more between correct waterings. Light intensity might be an issue as well. In early veg, I'm around 25% of finishing wattage. Hope that helps.

 

[Olezhkakot]

I grow in soil and water to 10% run-off, only when pots are very light. Over-watering has to do primarily with how often you water, not how much water you give. I don't know what media you're in. If that's soil, plants that small in pots that big might go a week or more between correct waterings. Light intensity might be an issue as well. In early veg, I'm around 25% of finishing wattage. Hope that helps.

Man, that helps for sure, medium is soil, thank you!

 

[freezeland2]

At those day time temps and RH that low those plants are in very high transpiration. Do you have anyway of determining your leaf temps? A IR thermometer would be your best friend right now.

 

[TSD]

I think 15 inches is probably a bit too close for that light and those young plants... and it definitely sounds like you're watering too frequently, the leaves look swollen, meaning they're overwaterd. You can't just go by the top of the soil. They need a dry period, let them be until the soil is light, then saturate. I routinely go a week between waterings when my plants are that small inside... fabric pots maybe less with good airflow, maybe 5 days, depends on the environment. Get a moisture meter to stab in the side of your pots till you get watering down.

 

[TSD]

Check out this thread for a good rundown on watering practices.

Marijuana Watering, how media, pot size/shape and environment affect it

Discuss different watering methods for growing your own weed from seeds. Our community members give helpful tips on how pot size and material, as well as environmental factors affect growing cannabis.

www.thcfarmer.com

 

[Olezhkakot]

At those day time temps and RH that low those plants are in very high transpiration. Do you have anyway of determining your leaf temps? A IR thermometer would be your best friend right now.

Can you elaborate a bit or reference some article on transpiration please? Never read about this

 

[Olezhkakot]

I think 15 inches is probably a bit too close for that light and those young plants... and it definitely sounds like you're watering too frequently, the leaves look swollen, meaning they're overwaterd. You can't just go by the top of the soil. They need a dry period, let them be until the soil is light, then saturate. I routinely go a week between waterings when my plants are that small inside... fabric pots maybe less with good airflow, maybe 5 days, depends on the environment. Get a moisture meter to stab in the side of your pots till you get watering down.

Thank you, I’ll try that strategy!

 

[TSD]

Transpiration is the movement of water out of the stomata of the leaves, the lower the humidity in the environment, the more water they transpire to cool themselves down.... basically lol.

Transpiration - What and Why? | Transpiration - Water Movement through Plants - passel

passel2.unl.edu

 

[steamroller]

Can you elaborate a bit or reference some article on transpiration please? Never read about this

Search VPD [ Vapor Pressure Deficit] .
You should be able to read room temperature, RH, and leaf temp.
Most use IR thermometers for leaf surface temps.

 

[freezeland2]

Can you elaborate a bit or reference some article on transpiration please? Never read about this

TSD posted a good link. There is also a lot of info on this forum about the importance of maintaining acceptable vpd levels for healthy transpiration. Search vpd. Your plants, based on your ambient temp range and low rh results in a very high vpd. What we do not know is the leaf temp offset. But if you are under a LED light, and keep temps around 80 degrees and rh of 60% you should land in a safe vpd.

 

[MIGrampaUSA]

Plants are not transpiring properly ... @TSD, @steamroller, @freezeland2 have all stated the same problem ... just a bit differently. Plant leaves look swollen. Could be over-watering, could be temps. Most likely its a combination of both. Fix the environmental issues and your watering practices may fall into line without any further action ... unless over-watering/watering too often is what has caused the problem in the first place

+1 for all three of those responses.

 

[TSD]

Here's a visual that shows where you should be in each stage and how to get there with proper temp and humidity.

 

[Olezhkakot]

Here's a visual that shows where you should be in each stage and how to get there with proper temp and humidity. View attachment 1278882

Man, much thanks, you brought my understanding to whole new level. I just measured the temp, the swollen leaves are about 26 and those who look okay are 25(77/78F)

 

[Olezhkakot]

Here's a visual that shows where you should be in each stage and how to get there with proper temp and humidity. View attachment 1278882

Ah okay, so as I can understand - I should either bring humidity to 60 or lower temperature to 61

 

[MIGrampaUSA]

I'm more inclined to say stop watering/feeding so often. I looked through your data. Temperatures are fine both day and night. 50% humidity is where I like to be (I prefer slightly dry over slightly humid) so the most likely cause for swollen droopy leaves is watering too frequently.

Do take leaf temperatures with a no contact infrared thermometer. If you don't have your leaf temps, you don't have the correct data to use the charts. In the meantime, give an extra day or possibly more between watering.

 

[TSD]

Ah okay, so as I can understand - I should either bring humidity to 60 or lower temperature to 61

Technically... but 61 is a bit chilly lol.

 

[TSD]

But I agree... it's pretty likely that you've been drowning your girls, they need a dry period so oxygen can return to the soil and the roots can take it up for the plant to use.

 

[TSD]

I'm more inclined to say stop watering/feeding so often. I looked through your data. Temperatures are fine both day and night. 50% humidity is where I like to be (I prefer slightly dry over slightly humid) so the most likely cause for swollen droopy leaves is watering too frequently.

Do take leaf temperatures with a no contact infrared thermometer. If you don't have your leaf temps, you don't have the correct data to use the charts. In the meantime, give an extra day or possibly more between watering.

I've gone 9 days between waterings in nursery pots with small plants, without getting too dry... little ladies just don't use water that fast.

 

[freezeland2]

I think you have enough good recommendations in this thread to get that plant back on track. Got to let it dry back between watering. Get your rh up to get the transpiration in the .4 - .8 kPa range with leaf temps 75 - 77. If you are under LED the ambient temp would run about 79 - 81 degrees.

Anyway, good luck. You got this.