Can a humidifier damage a plant?

Just wondering if running a humidifier basically all day can have negative affects on leaves or the plant itself.
I’ve had some weird leaf issues throughout my grow, haven’t been able to pinpoint an actual cause and thinking it may be from excess cal in the water going through my humidifier.
I could be way off, but still curious if humidifier can be bad in the long run.

No. Just make sure to have good airflow to avoid mold.

Username85 said:

Just wondering if running a humidifier basically all day can have negative affects on leaves or the plant itself.
I’ve had some weird leaf issues throughout my grow, haven’t been able to pinpoint an actual cause and thinking it may be from excess cal in the water going through my humidifier.
I could be way off, but still curious if humidifier can be bad in the long run.

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Include a picture, it'll help the others get better idea of what's going on. Some extra information such as temperature, humidity light type and distance. The more Info you add the better.

Turpsnstuff said:

Include a picture, it'll help the others get better idea of what's going on. Some extra information such as temperature, humidity light type and distance. The more Info you add the better.

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I’ve posted on this same issue a few times and I’m not sure a consensus was ever really reached.
5 gal fabric pots (recently repotted from 3 gal)
FFOF/FFHF, watering every 3 days at this point (1.5 gal per plant) no nutes yet
SF1000, 3x3x6 tent, day temps/rh: 78~82 60% (changed recebtly to 45% humidity, flipping to 12/12 tomorrow) Night time temps 72~74 (same humidity). 6” inline exhaust, 2 clip fans acting as intake, 5 clip fans spread throughout tent, ph between 6.4~7

ive had crunchy leaves, rust looking spots-has happened on new growth and old growth-not an put of control issue, but would like to pinpoint it. Suggestions I’ve heard were ph fluctuating, cal-mag, or my light-not sure if those are the issue

Try phing to 6.5 rather than 7.0. For micros

plants look good.
If you get the leaves wet when watering/feeding with lights on you can get weird issues
old growth not getting much light dies sometimes, best to just pluck the odd old shaded dying one or 2 every now and then and not lose too much sleep over them.
I cant answer the humidifier question because i dont use them. My rh is around 30% and my plants dont seem to mind.

As long as your RH doesn't get too high with it on all day, I don't see why it would harm it. Seems to be something related to watering/ph. I see some drooping fan leaves which would indicate watering issues, and the brown spots on some fan leaves that would indicate possible ph fluctuations. The crunching of the leaves is probably a result of a little bit of both issues combined.

Sometimes you can also get "chemical burn" from foliar sprays or unintentionally from watering when the lights are on, but I doubt it would suck the whole leaf dry.

What's that white stuff on the leaf on the top of the picture #1?

BestBudz_Grow said:

What's that white stuff on the leaf on the top of the picture #1?

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Some of the leaves that are being affected get a waxy look in spots, not the entire leaf though. The white spots are a reflection off the real waxy looking spots-almost as if it’s honeydew from pests, but haven’t seen any evidence of pests in the tent. Ph fluctuations I can believe considering I wasn’t ph’ing at all in the beginning. Working with a ph drip kit so dialing in precisely around 6.5 is hard lol.
I’ve tried not stressing over the issues since the plants are still growing nicely considering, but would like to have an idea so I can watch for next time

My humidifier has white buildup, I assume cal, which I’ve noticed on top of leaves in the tent. That made me think maybe over time with enough cal in the air it might start affecting the plants.

It sounds like you're using an ultrasonic humidifier. It's much better to go with an evaporative humidifier rather than the ultrasonic variety because ultrasonic humidifiers can eventually create several mineral deposit issues like clogging in the mechanics of the unit, chalky whiteness that clogs carbon filters, dulling of the reflective material on your walls, clogging the stomata on your plants' leaves etc. This might be avoided by using nothing but distilled water which might be a PITA but it could very well solve your problem.

Just Be said:

It sounds like you're using an ultrasonic humidifier. It's much better to go with an evaporative humidifier rather than the ultrasonic variety because ultrasonic humidifiers can eventually create several mineral deposit issues like clogging in the mechanics of the unit, chalky whiteness that clogs carbon filters, dulling of the reflective material on your walls, clogging the stomata on your plants' leaves etc. This might be avoided by using nothing but distilled water which might be a PITA but it could very well solve your problem.

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Thank you for the info, I didn’t know there were different types of humidifiers, never gave that much thought I guess. Thankfully I’m passed the point of having to use my humidifier. If that makes no change at least I know what to fix for next time.

Username85 said:

Thank you for the info, I didn’t know there were different types of humidifiers, never gave that much thought I guess. Thankfully I’m passed the point of having to use my humidifier. If that makes no change at least I know what to fix for next time.

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Especially if you're on well water or some kind of water source with a water softener system. The added salt content along with your already high ppm puts a lot of "debris" in the air.

BestBudz_Grow said:

Especially if you're on well water or some kind of water source with a water softener system. The added salt content along with your already high ppm puts a lot of "debris" in the air.

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Yeah I’ve noticed quite a bit of “debris” on top of the canopy-was reallll nervous when I first saw it

Plants look good, switch to zero ppm water for your humidifier and you won’t get that mineral buildup, also your humidifier will last longer. Otherwise plants look good. Think of em like people we’ve got spots and blemishes, not every leaf will be perfect. Don’t sweat the small stuff.