Week 6 hydro White mold.

Hi everyone.

Im running 3 plants in a g-tools 60x60 grow box going into week 6 flowering today. I use drip automatic irrigation watering with circulating tank.
Everything have been running great and plants are looking healthy. Today I noticed white mold on some roots and pebbles. Panic! What do I do? Do I need to throw everything away and start over again? Can this be saved?

Dont freak yet!

Its hard to tell from those pics...are you sure thats mold and not white fuzzy hairs? Can you get a clearer picture - close up maybe with a macr lens or USB scope?

These are fuzzy hairs on roots. they are a GOOD thing.


If you do have white mold, thats very unusual on roots. In fact, I cant remember seeing anyone with white mold before on roots. Buds yes, but roots no.

the white stuff on the rocks is almost certainly just mineral deposits and nothing to worry about really.

Edit: On second look, that doesnt really look like fuzzy hairs, but its hard to be sure. Could it be insect larva or eggs maybe? You really need to get some better pics.

Looks like PM. Never seen it on roots though. Might be bad or beneficial, hard to tell. How does the rest of the plant look? How does it smell? They should not be standing in runoff/stagnant water.

Thanks guys for replying.

I removed the white pebbles and inspected them, they are furry white as in mold, not minerals.

Everything else looks and smells great. Plants are in extraordinary shape, buds are forming as expected. Water in reservoir looks and smells fine. Temperature optimal.

I found another thread https://www.rollitup.org/t/mold-in-hydroponics.790105/ discussing similar. I followed the advices from this and used hydrogen peroxide to clean the tray and water reservoir. I also sprayed the pebbles, roots and airpots with diluted hydrogen peroxide 1.5%. Also added another fan directly pointed at the top layer of the pebbles to ensure they are dry.

Lets see if this works.

nute build up on growing medium

oops didnt read that last post, ignore that last remark. smashed again

When i get mold popping up like that, i would increase air circulation and lower humidity a lil if possible

Cut off the white stuff and you should be good to go iv ran into this a few times

Wastei said:

Looks like PM. Never seen it on roots though. Might be bad or beneficial, hard to tell. How does the rest of the plant look? How does it smell? They should not be standing in runoff/stagnant water.

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I have drippers going 20 min every hour when light is on. The drip tray then collects overflow of water that goes back in tank. But, its always 0.5 inches of water left on tray.

Crazy_Ace420 said:

When i get mold popping up like that, i would increase air circulation and lower humidity a lil if possible

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I have 3 fans running. Humidity is a problem, get around 70-80% which is really bad week 6 flowering. Don't know how to get it down.

drip tray that collects overflow could be partaly responsible for that, not saying its much ,but a little bit

starship111 said:

I have 3 fans running. Humidity is a problem, get around 70-80% which is really bad week 6 flowering. Don't know how to get it down.

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Buy a dehumidifier. There is no way you'll finish your flower cycle without mold on your flowers running 70-80% humidity. Buy a dehumidifier. Like right now. Increase air flow too. You gotta get that under control ASAP!

3 days of 60% rh at 80f in week6 flower I had to flush a 4x4 tent that was stacked to the gills listen to this man these are facts....it’s all fun and games untill you watch your hard word twirl around the shitter

U. We’d to get that shit under control ASAP like fucking yesterday my dude or your guna kick your self in the ass like I did hear a pic of my crop I flushed......3 days is all it took this shit goes from un noticeably untill it blooms then boom it’s everywhere trust me

Could this be extra Ca build up from hard water?

Bite the bullet and drop the 250$ on a bid dehumidifier and place it in the tent running 24/7 if you don’t have room jerry rig it so the fan inside the tent is blowing air out of the tent makeing negativ pressure and take another piece of duck work and have the dehumidifier blowing air into the tent the negative pressure will suck it in if it’s 60%rh outside the tent it will be 45% inside this is how I do it when their no room in the tent just make sure your dumping it first thing in morning and right before you go to bed so it’s running non stop

jonnynobody said:

Buy a dehumidifier. There is no way you'll finish your flower cycle without mold on your flowers running 70-80% humidity. Buy a dehumidifier. Like right now. Increase air flow too. You gotta get that under control ASAP!

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I will do it first thing in the morning. This crazy humidity is not working out.

starship111 said:

Hi everyone.

Im running 3 plants in a g-tools 60x60 grow box going into week 6 flowering today. I use drip automatic irrigation watering with circulating tank.
Everything have been running great and plants are looking healthy. Today I noticed white mold on some roots and pebbles. Panic! What do I do? Do I need to throw everything away and start over again? Can this be saved?

Click to expand...

i'd be double checking your plants for mold too. spores spread easy and rapidly.

It can also be very hard to detect early on. Sometimes the only warning you have is maybe a single sugar leaf on a bud looking a bit off. Then you pry it open and find that crap deep inside.

Ive only lost one plant to PM, but it really sucked. I usually have just the opposite problem of too low humidity.

Im a little worried about my current grow. I decided to try one of those ultrasonic foggers to raise the humidity durring the early part of this grow. My RH controller had a bad sensor at first, and the humidity went way too hi. Plus the fogger was blowing tiny droplets on to the plants leaves instead of converting that water into actual humidity. I started to see signs of mold on the leaves after just a couple of days. This was in early veg - long before buds formed. Ive been ruthlessly cutting off leaves with any hint of mold, but Im still worried it will be hanging arroud as the new buds form.