Grow Room Previously Had Mold

auto_grow

Member
TL;DR: Nearly finished install and learned room previously had in-wall mold from flood.

Setup includes new aircon, dri-eaz dehumid, cch20 pro, closed room w/ co2 via Autopilot, etc. etc., just over 30 square meters (~20'x20') and just now learning when replacing the original ducting (oops! should have started there) there was a flood and visual signs of (poorly done) mold remediation.

Mold CFU and in-wall air sample inspection is this week and pretty sure the outcome will be "YOU'VE GOT MOLD!".

The room is sealed (appropriate paint, vapor sealing, etc) and environment is controlled. If continued, and plans are to continue, will be sending samples after harvest between each clean for TYM testing (aka: is there mold on your cannabis test).

1) What mold battles should be expect?
2) Anyone deal with a similar situation?

...and I don't know how else to word it and did run searches first, but:
3) Links to advice or grow journals for successful growing in a environment previously with mold?
Controlling the mold spread/battle if that is a thing.

I can't find any advice other than throw away / harvest early. Hope with your help we can roll this problem up with a positive outcome!
 

Renfro

Well-Known Member
Mold grows because it has food and moisture. So say wood / drywall and the flood. If the walls are dry then there should be no new mold growth.

The humidity from the grow could provoke growth to restart.

I would suggest using Physan 20 solution to spray the areas that had the mold, and everywhere honestly. That shit will stop mold in it's tracks. Then you have a good room to start with. Using the Physan between runs to clean is highly advised.
 

vertnugs

Well-Known Member
Ozone machine,shock the entire area.Run a/c on recirculate.

Adding a u/v light setup,diy/store bought what ever for added protection and some peace of mind.
 

indianajones

Well-Known Member
Hey @auto_grow I own a mushroom farm and this is a daily battle for us.

IMO, the best product you could use in this situation is gaseous chlorine dioxide. I use bio-cide brand and citric acid as the activator. Since it's a gas it will sanitize every nook and cranny that touches air, and possibly even in the walls, depending on how they're seamed at the top/bottom.

You should just replace the drywall and use that time to examine the studs and see if they also need work. Drywall work is two, three days max, then no more worries. If you lose even one plant it's worth more than the cost of drywall.
 

indianajones

Well-Known Member
TL;DR: Nearly finished install and learned room previously had in-wall mold from flood.

Setup includes new aircon, dri-eaz dehumid, cch20 pro, closed room w/ co2 via Autopilot, etc. etc., just over 30 square meters (~20'x20') and just now learning when replacing the original ducting (oops! should have started there) there was a flood and visual signs of (poorly done) mold remediation.

Mold CFU and in-wall air sample inspection is this week and pretty sure the outcome will be "YOU'VE GOT MOLD!".

The room is sealed (appropriate paint, vapor sealing, etc) and environment is controlled. If continued, and plans are to continue, will be sending samples after harvest between each clean for TYM testing (aka: is there mold on your cannabis test).

1) What mold battles should be expect?
2) Anyone deal with a similar situation?

...and I don't know how else to word it and did run searches first, but:
3) Links to advice or grow journals for successful growing in a environment previously with mold?
Controlling the mold spread/battle if that is a thing.

I can't find any advice other than throw away / harvest early. Hope with your help we can roll this problem up with a positive outcome!
1. Black pin mold (Stachybotrys chartarum), which is extremely toxic to some folks.

2. See my above post. You also need to add enough heat so that you don't have more than 2-3° temperature swing from day to night. Temperature swings will lead to condensation.

3. I just replaced the damaged materials in our grow and continued working.
 

Just Be

Well-Known Member
Here's a second vote for using an ozone generator. You can find one that uses ambient air (as opposed to some models that you hook an oxygen tank up to) ..for cheap on Amazon. A2Z Ozone's Aqua-6 machine is like 70 bucks and will serve you for years to come. On a side note, I've heard of ozone generators that require an oxygen tank that have been used indoors but have actually killed mildew growing on the exterior vinyl siding.
 

auto_grow

Member
Ozone generator and air filtration are already installed. Currently no u/v light.

Thinking replacing the drywall and any studs needed is the appropriate next step but that means a teardown and nearly complete reinstall.

I'll look more into the temperature swings. Is that 2-3°C or 2-3°F?

Also will look into gaseous chlorine dioxide.


Thank you all!
 

vertnugs

Well-Known Member
What size ozone?Enough mg/h to give a good 24 hr shock treatment?I think it's some thing like 1,000 mg/h per 100 sf if memory serves correct,doesn't take much.
 

sandman83

Well-Known Member
Hey @auto_grow I own a mushroom farm and this is a daily battle for us.

IMO, the best product you could use in this situation is gaseous chlorine dioxide. I use bio-cide brand and citric acid as the activator. Since it's a gas it will sanitize every nook and cranny that touches air, and possibly even in the walls, depending on how they're seamed at the top/bottom.

You should just replace the drywall and use that time to examine the studs and see if they also need work. Drywall work is two, three days max, then no more worries. If you lose even one plant it's worth more than the cost of drywall.
I had to deal with mold in a house after hurricane, I would 2nd the opinion of yanking the drywall and replacing. That stuff is like a sponge at the bottom when it gets wet. Studs are probably fine but I would spray treat them and then re-drywall the room.
 

sandman83

Well-Known Member
@sanman83 and @indianajones, even if sealed already?
Just from my experience, the base boards and floors were what held the nastiest sludge and damage. Visible parts of the "ok" rooms were disgusting once you saw the back of the drywall. I was grossed out and just demo'd the whole thing and replaced.

Were any of the wet walls insulated?
 

sandman83

Well-Known Member
Pulled floor already and trim. It's the drywall I am wanting to avoid replacing.
to each their own, to me you already did the hardest part, taping and floating some fresh drywall is cheap and easy. I'm no expert but I can do a passable job for home inspections. Throw some orange peel texture and no one will ever know ;).



Perhaps just cut a small hole and visually inspect behind? Could be worried about nothing but I'd want peace of mind.
 

indianajones

Well-Known Member
Cut out a section from stud to stud 30cm/12° high and check inside the wall. It's easy to replace a square chunk from stud to stud and you will know for sure.

I've also worked doing house remodels and maintenance for a landlord. I've seen enough water damage to know it almost always needs replaced. The mold that grows in drywall is very toxic.

Stachybotrys chartarum,[note 1] (/stækiːˈbɒtrɪs/ /tʃɑːrˈtɛərəm/, stak-ee-BO-tris char-TARE-əm[1]) also known as black mold or toxic black mold, is a variety of microfungus that produces its conidia in slime heads. It is sometimes found in soil and grain, but the mold is most often detected in cellulose-rich building materials from damp or water-damaged buildings.
 
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