Is This Powdery Mildew or..?

My girls are currently in the seedling stage, had a high humidity until recently but lowered to 50's right now...
A few days ago I noticed something strange on my fans... then upon checking where the fan blows, I saw that a white dust seemed to be forming on my rdwc (currently not in use) and on my clear propagator cover which happened to be just left under where the fan blows after I removed it from the propagator. The girls seemed fine with no sign of this dust atm.
I took the girls out, dismantled the fan, cleaned all the tent and everything around with 3% hydrogen peroxide. Washed the propagator with bleach and rinsed it thoroughly. Then mixed the peroxide with 9 parts water and sprayed the girls with it...

And when the lights were out, I took the girls out to another room and upped the temperature to above 90f for a few hours, as high temperature is said to kill powdery mildew for sure.

It all seemed fine for a few days but today I noticed the white dust slowly forming again in the propagator walls, it almost feels like residue dust which you can wipe with your finger (and you actually can), but I didn't use anything that can leave a residue as far as I know.

Here are some pictures from when I noticed this happening the first time. Any ideas to what this might be and any suggestions? The girls are still fine and this dust is not forming on the leaves right now but they are so little and I am not sure what might happen next...

I thought this was powdery mildew but is it normal that I only see it on the equipment?

post a pic without light on... If u had a humidifier inside it might be from that but that on the walls looks like a colony . Did you clean ur grow space before starting the grow ? Do you wash or sanitize ur hands when u work with ur plants ?

ikushy420 said:

post a pic without light on... If u had a humidifier inside it might be from that but that on the walls looks like a colony . Did you clean ur grow space before starting the grow ? Do you wash or sanitize ur hands when u work with ur plants ?

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Exactly, those look like colonies to me as well, that's why I posted the pic... but I did clean the grow space before starting out and yes I do wash my hands with soap each time I get in there.

I am running a humidifer but I sprayed that with h2o2 before turning it on first time as well. Now I'm thinking if that might be some calcium build up from the tap water I use in humidifer, being spread around. But then again, those colony looking patches

And I doubt some residue from the humidifer spreading around would cause those webby builds on the fans. :/

vorus said:

Exactly, those look like colonies to me as well, that's why I posted the pic... but I did clean the grow space before starting out and yes I do wash my hands with soap each time I get in there.

I am running a humidifer but I sprayed that with h2o2 before turning it on first time as well. Now I'm thinking if that might be some calcium build up from the tap water I use in humidifer, being spread around. But then again, those colony looking patches

And I doubt some residue from the humidifer spreading around would cause those webby builds on the fans. :/

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Yeah thats what i was going on about the calcium build up cause i have alot of it in grows :,) . The circle ones look very suspicous id clean it as fast as posible the whole grow space equipment with sanitizing wipes cleaner whatever has alcohol in it or something to get rid of 99.99% . And i keep a close eye since spores could be everywhere. Cause usually when u spray water it leaves dripping calcium trails and not circles. Hope you get this undercontrol . Btw that profile pic tho. :,D 10/10

ikushy420 said:

Yeah thats what i was going on about the calcium build up cause i have alot of it in grows :,) . The circle ones look very suspicous id clean it as fast as posible the whole grow space equipment with sanitizing wipes cleaner whatever has alcohol in it or something to get rid of 99.99% . And i keep a close eye since spores could be everywhere. Cause usually when u spray water it leaves dripping calcium trails and not circles. Hope you get this undercontrol . Btw that profile pic tho. :,D 10/10

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Yeah, now after you mentioned, I took a new picture with normal light and this time, the propagator seems clean of those colony looking circles... this got me thinking that the propagator was not so clean last time but the white dust from the calcium was just a coincidence and I might have got rid of those colonies but the dust came back because of the tap water I used in humidifier. I just filled it with distilled water and I'll still clean the tent all over once again... let's see where this takes me.

Does this look like your calcium build up? :


Oh and thanks about the profile picture LOL

vorus said:

Yeah, now after you mentioned, I took a new picture with normal light and this time, the propagator seems clean of those colony looking circles... this got me thinking that the propagator was not so clean last time but the white dust from the calcium was just a coincidence and I might have got rid of those colonies but the dust came back because of the tap water I used in humidifier. I just filled it with distilled water and I'll still clean the tent all over once again... let's see where this takes me.

Does this look like your calcium build up? :
View attachment 4845532

Oh and thanks about the profile picture LOL

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Yes the calcium build up looks like that when you swipe it with ur finger usualy fine dust will be on ur finger. Not sure what those other white spots are dried up water ?

ikushy420 said:

Yes the calcium build up looks like that when you swipe it with ur finger usualy fine dust will be on ur finger. Not sure what those other white spots are dried up water ?

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Yeah I've been feeding them with a syringe and it spills around a bit, thats that.
The dust is just as you explained... that is sooooo good to know. Thanks a lot