White spots on leaves

kowato12 · Jun 9, 2020

Hey everyone,

so my first plant seems to be thriving! HOWEVER, i am concerned about these little white spots on the leaves. I've noticed them before but not to this extent. When i brush them on the leaf they seem to disappear pretty easily. I sprayed neem oil last week on the leaves, but i can't see any spider mites. I'm wondering if its possibly related to the humidifier I have next to the plant with the fan blowing the mist from the humidifier onto the plant resulting in some kind of deposit.

Anyone out there think they could help me? Really hope its not spider mites or mold. (It's all the same plant)

Anthem · Jun 9, 2020

Are you using tap water in your humidifier? Water is the PPM of your tap water?

kowato12 · Jun 9, 2020

Anthem said:
Are you using tap water in your humidifier? Water is the PPM of your tap water?

I am using tap water, but I'm adding some pH down (acidic solution) to it so the pH looks around 6.0.

I'm only using pH for the soil water.....Would adding pH solution to the humidifier water solve this problem?

Also thanks for replying so quick!

kowato12 · Jun 9, 2020

Anthem said:
Are you using tap water in your humidifier? Water is the PPM of your tap water?

Also not sure how to calculate the PPM of my water. Should I get something to test that? Also would using a Brita to filter the water be useful?

mfed · Jun 10, 2020

Look like wall plaster, but maybe powdery mildew from last picture right side or maybe mites, try use forbid before flower

kowato12 · Jun 10, 2020

mfed said:
Look like wall plaster, but maybe powdery mildew from last picture right side or maybe mites, try use forbid before flower

the white mark on the last picture on the right side is from me rubbing one of the white dots. I can't spot any mites (i sprayed neem oil today just in case). I really believe its what ^ said. seems to increase when the humidifier is on, hopefully its just deposits from the humidity on the leaves

mfed · Jun 10, 2020

kowato12 said:
the white mark on the last picture on the right side is from me rubbing one of the white dots. I can't spot any mites (i sprayed neem oil today just in case). I really believe its what ^ said. seems to increase when the humidifier is on, hopefully its just deposits from the humidity on the leaves

Actually...If it came from humidity might look like larger area, not a spot , I don’t know if u could understand . By the way , why do u use the humidifier?

kowato12 · Jun 10, 2020

mfed said:
Actually...If it came from humidity might look like larger area, not a spot , I don’t know if u could understand . By the way , why do u use the humidifier?

i use it to keep a humidity between 40-60% but i'm about to turn off my humidifier as the humidity in my tent seems to be around 40% on most days anyways.

idk, i don't have any reason to believe its spider mites as theres no damage to the leaf as soon as i wipe off the wipe "deposit". hopefully turning off the humidifier will change all this

mfed · Jun 10, 2020

kowato12 said:
i use it to keep a humidity between 40-60% but i'm about to turn off my humidifier as the humidity in my tent seems to be around 40% on most days anyways.

idk, i don't have any reason to believe its spider mites as theres no damage to the leaf as soon as i wipe off the wipe "deposit". hopefully turning off the humidifier will change all this

Then probably white powder, ez to fix on early, try close every fan after light off , not humidifier.
That why your spot looks small, probably your plant are small?

CosmoGrows · Jun 10, 2020

@kowato12,

Look on amazon for a PPM Meter, or TDS meter rather. Some reliable ones are like Bluelabs.

From what i gather from your pictures it seems like you have the same issue i do. I have 300PPM Tap water, and when i use tap water in my humidifers i will get a white buildup on my plants, kind of like small little white rocks. When you rub it off and its on your hands, it feels like your rubbing sand, rock, or something gritty together i guess, you can smoothly wipe your fingers, you get a weird feeling on your hands. ive looked at it under a 1200X microscope to verify.

By looking at this, you would think i have a case of powdery mildew arising. Thats not the case,i have resolved this issue buying distilled water for my humidifiers.

Im not saying, dont be on the lookout for PM. As growers, we should always be watching for error, keep an eye on it. But, if you find out what ppm your running, and it runs high, i would say humidifier dust is your case too.

Stay on the lookout, dont keep track of it. Look for growth if you see more arising, maybe grab a microscope and compare it to the pictures above.

kowato12 · Jun 10, 2020

mfed said:
Then probably white powder, ez to fix on early, try close every fan after light off , not humidifier.
That why your spot looks small, probably your plant are small?

what do you mean try and close every fan after light off? i typically do a 20/4 light schedule by the way, i keep my carbon filter/inline fan on 24/7 as well as my clip fan pointing above the canopy.
fyi i just wiped off the white spots for the majority with a glove and turned humidifier off. i did that earlier today and they seemed to come back after 8 hours but now that the humidifier is off i'll see in the morning if any white spots came back. here's a picture of my leaves after i wiped them off.

my plants an autoflower gorilla glue 4 weeks in, so still relatively small but its growing in a 5 gallon pot.

kowato12 · Jun 10, 2020

CosmoGrows said:
@kowato12,

Look on amazon for a PPM Meter, or TDS meter rather. Some reliable ones are like Bluelabs.

View attachment 984166

From what i gather from your pictures it seems like you have the same issue i do. I have 300PPM Tap water, and when i use tap water in my humidifers i will get a white buildup on my plants, kind of like small little white rocks. When you rub it off and its on your hands, it feels like your rubbing sand, rock, or something gritty together i guess, you can smoothly wipe your fingers, you get a weird feeling on your hands. ive looked at it under a 1200X microscope to verify.

View attachment 984167

By looking at this, you would think i have a case of powdery mildew arising. Thats not the case,i have resolved this issue buying distilled water for my humidifiers.

Im not saying, dont be on the lookout for PM. As growers, we should always be watching for error, keep an eye on it. But, if you find out what ppm your running, and it runs high, i would say humidifier dust is your case too.

View attachment 984168

Stay on the lookout, dont keep track of it. Look for growth if you see more arising, maybe grab a microscope and compare it to the pictures above.

thanks!!!! going to purchase one right away. I live in Los Angeles so I have a feeling its something to do with the tap water (since i'm not filtering it, only changing the pH slightly). I just wiped all the tiny white spots off the leaves gently, and turned my humidifier off. going to see if white spots are back in the morning and hopefully they aren't.

speaking of water ppm, could this affect my plant when i'm watering it as well?

mfed · Jun 10, 2020

I mean If humidity high makes white powder , also tap water . can I see your monitor about humidity? and try pure water .

CosmoGrows · Jun 10, 2020

kowato12 said:
fyi i just wiped off the white spots for the majority with a glove and turned humidifier off. i did that earlier today and they seemed to come back after 8 hours but now that the humidifier is off i'll see in the morning if any white spots came back. here's a picture of my leaves after i wiped them off.

Looking clean, sounds like a decent idea. Keep us updated with results.

kowato12 said:
thanks!!!! going to purchase one right away. I live in Los Angeles so I have a feeling its something to do with the tap water (since i'm not filtering it, only changing the pH slightly). I just wiped all the tiny white spots off the leaves gently, and turned my humidifier off. going to see if white spots are back in the morning and hopefully they aren't.

speaking of water ppm, could this affect my plant when i'm watering it as well?

So when it comes to Tap water PPM,normally alot of it is cal-mag, which essentially, is good for your plants, so it could be decent to have higher tap water ppm, but ideally i believe the happy number is lower, around 150ppm or so.
and yes, i would say, being in los angeles, your water is probably more on the hard side. Not a bad thing, i use hard water for my grow and have had no negative effects as far as i know. but like i said, its been awhile since ive researched that magic ppm number for tap water, and i dont remember. (i just use my tap ppm and go on with my day)

So, when you go to add nutrients, and lets say you have 1000ppm nutrient solution, youll need to remember that X amount of that is tap water PPM of majority cal-mag.

Check out an article posted on Royal Queen,

Cannabis & Water Quality Part 2: PPM & EC - RQS Blog

Water quality is an essential consideration when it comes to advanced cannabis growing. In part two of out guide, we look at PPM and EC.

www.royalqueenseeds.com

kowato12 · Jun 10, 2020

CosmoGrows said:
Looking clean, sounds like a decent idea. Keep us updated with results.

So when it comes to Tap water PPM,normally alot of it is cal-mag, which essentially, is good for your plants, so it could be decent to have higher tap water ppm, but ideally i believe the happy number is lower, around 150ppm or so.
and yes, i would say, being in los angeles, your water is probably more on the hard side. Not a bad thing, i use hard water for my grow and have had no negative effects as far as i know. but like i said, its been awhile since ive researched that magic ppm number for tap water, and i dont remember. (i just use my tap ppm and go on with my day)

So, when you go to add nutrients, and lets say you have 1000ppm nutrient solution, youll need to remember that X amount of that is tap water PPM of majority cal-mag.

ok awesome. would a BRITA assist with lowering ppm of tap water adequately?

also since this was my first grow and all hydro stores around me were closed during quarantine, SO i went the easy route and ordered from this website:

They said their soil came with all the nutrients necessary, so I haven't even bothered with adding additional nutrients or feeding my plant anything else besides light and water to be honest. On my next grow i definitely want to go out and by my own soil and nutrients etc.

kowato12 · Jun 11, 2020

CosmoGrows said:
Looking clean, sounds like a decent idea. Keep us updated with results.

So when it comes to Tap water PPM,normally alot of it is cal-mag, which essentially, is good for your plants, so it could be decent to have higher tap water ppm, but ideally i believe the happy number is lower, around 150ppm or so.
and yes, i would say, being in los angeles, your water is probably more on the hard side. Not a bad thing, i use hard water for my grow and have had no negative effects as far as i know. but like i said, its been awhile since ive researched that magic ppm number for tap water, and i dont remember. (i just use my tap ppm and go on with my day)

So, when you go to add nutrients, and lets say you have 1000ppm nutrient solution, youll need to remember that X amount of that is tap water PPM of majority cal-mag.

Check out an article posted on Royal Queen,

Cannabis & Water Quality Part 2: PPM & EC - RQS Blog

Water quality is an essential consideration when it comes to advanced cannabis growing. In part two of out guide, we look at PPM and EC.

www.royalqueenseeds.com

hey @CosmoGrows here's an update on the plants leaves. turning the humidifier off and then when back on using a lower humidity setting (40%) and filtered water from BRITA seemed to have stopped the "white spots" from showing up AS MUCH. It's not nearly as bad but still have tiny ones on some leaves. So i'm guessing it was calcium deposits or other mineral deposits from the humidifier water. Thanks for helping out with that.

Below are some pics of the leaves today. I did HOWEVER notice this on a couple of my leaves. Any chance you're able to identify what this is? The "blotches" are in the last picture. Hopefully its just water drops from spraying neem oil a couple days that could of simply burned the leaves. But I'm not so sure.

Best,
Tom

Anthem · Jun 11, 2020

Looks like tap water is evaporating on your leaves and causing the white deposits. I would leave the humidity high at least 60 percent until you get about 1/3 to 1/2 of the way thru flower. If you can look up VPD, Vapor pressure Deficit and try to follow based on your temperature in the grow. Also someone mentioned to turn off fans and close vents with lights out. Please do not do this. It will create a humidity spike and could cause PM. Pm does not like to grow in conditions that have a relative humidity under 50 percent. Once your buds are about 1/3 or 1/2 thru the flowering process you need to keep mind of the humidity. PM and Bud Rot love the high humidty and bud rot has a nasty habit of forming on the best colas. Good luck with your grow!!!!!!!!!!

kowato12 · Jun 12, 2020

Anthem said:
Looks like tap water is evaporating on your leaves and causing the white deposits. I would leave the humidity high at least 60 percent until you get about 1/3 to 1/2 of the way thru flower. If you can look up VPD, Vapor pressure Deficit and try to follow based on your temperature in the grow. Also someone mentioned to turn off fans and close vents with lights out. Please do not do this. It will create a humidity spike and could cause PM. Pm does not like to grow in conditions that have a relative humidity under 50 percent. Once your buds are about 1/3 or 1/2 thru the flowering process you need to keep mind of the humidity. PM and Bud Rot love the high humidty and bud rot has a nasty habit of forming on the best colas. Good luck with your grow!!!!!!!!!!

Thanks, since i filtered the water before I put it in the humidifier I've had no issues with the deposits anymore.
On the humidifier I leave the humidity setting on 35% and then my humidistat/thermometer in the tent says the humidity is usually around 50-55%. I'm thinking about completely turning off the humidifier once it hits the flowering stage, just because my tent humidity with the humidifier off already sits around 30-40%

i always have my inline fan and clip fan going when the lights are out. I'm heading into week 5 next Tuesday, so my watering has increased as well. I keep the LED ufo light on no less than 20 hours on a day now

here are some photos today after spraying the neem oil 2 days ago. It seems like more leaves have these kind of blotches as compared to before. Could it just be the neem oil solution drying up the leaves? Or are these blotches / yellow leaf (first pic) a result of under-watering since my plant is getting bigger?

Golfr323 · Mar 31, 2022

Would you say I have the same problem guys pls let me know what you think

White spots on leaves

White spots on leaves

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