Insects and molds can spoil the substrate and lower your yield.
The most effective way to deal with this problem is a combination of good hygiene and the right chemicals, but not chemicals alone.
First of all, the grow room itself matters. Cracks in doors and windows are where insects and spores come from, so everything needs to be sealed and repaired. There is no sense in covering walls with foil or other insulating materials — moisture will collect behind it, and mold will only spread faster.
💡In fact, mold will not grow in your room at all if the ventilation provides proper air exchange, even at high humidity.
📌 About ventilation and air exchange.
It’s also important not to use chemicals “just in case.” Frequent treatments do more harm than good.
They kill weak, harmless organisms and leave free space for aggressive mold strains that compete with oyster mushroom mycelium. This is why unreasonable disinfection often gives the opposite result.
Let's look at what chemicals are used to cultivate oyster mushrooms.
📌How to get rid of insects, read here
Table of Contents:
About formalin
Formalin (a 40% solution of formaldehyde with 8% methyl alcohol) is sometimes used in mushroom farms, but I believe it should not be used for oyster mushrooms.
Unlike champignon (button mushrooms), oyster mushrooms are less sensitive to molds, and formalin is extremely toxic.
▶️It has long-term effects on health, including allergies and chronic problems, and over time it accumulates in the body. For these reasons, formalin is not acceptable in oyster mushroom production.
Disinfectants are useful because they kill not only molds but also many bacteria and even spores. The main thing is to choose products that are effective against mold spores, safe for people, and suitable for closed rooms.
For small farms, there’s no need to look for expensive industrial products.
▶️The most well-known option is 70% isopropyl alcohol.
It’s very popular among small growers because it’s easy to find and convenient to use. You can wipe down tools, thermometers, sensors, knives, or even gloves during inoculation.
It also works well on plastic or metal surfaces where you don’t want excess moisture.
💡But keep in mind that alcohol evaporates quickly, so it’s suitable only for quick spot cleaning.
For thorough room disinfection, all you really need is to alternate between hydrogen peroxide (5%) and a chlorine-based cleaner like bleach.
▶️Peroxide works well against spores, leaves no smell, and is easy to find.
▶️Chlorine products don’t always act on all spores, but they’re cheap, simple to use, and help maintain cleanliness.
▶️For deeper cleaning — for example, during seasonal maintenance or before starting a new batch — you can use a disinfectant based on peracetic acid.
This is all you really need to keep your rooms clean without unnecessary chemicals or expenses.
Disinfectants are used for treating rooms, ventilation ducts, and filters. They can be sprayed through the ventilation system during recirculation or simply applied manually with a sprayer.
⚠️Use a gas mask and chemical protection suit!
After steaming or heat treatment, clean the steaming area and remove wet lumps of substrate.
Containers and tunnels should be rinsed thoroughly, and then disinfected with peroxide or bleach solution.
About once a month it is useful to apply peracetic acid as a preventive measure.
✅It’s worth mentioning that using fungicides such as benomyl or foundationazole in the substrate does not make sense: they decompose in alkaline conditions and do not give any effect.
Always inoculate substrate in freshly washed clothes that you use only in this room.
Don’t leave during the process, and after work soak the clothes in bleach solution, then rinse and wash.
Walls, floors, and equipment can be treated with peroxide or bleach.
✅After every inoculation, it’s important to do a full wet cleaning with bleach solution (diluted according to the instructions). This prevents mold and keeps the room safe in high humidity.
⚠️If you are working with sterile substrate (autoclave or even pressure cooker), peroxide disinfection of the inoculation room should also be done every time.
For regular non-sterile substrate, if the quality is stable, preventive treatment once a month is enough.
You can alternate products — for example, peroxide one time and bleach the next.
Never leave leftovers of substrate, bags, tape, or tools in the room.
▶️In high humidity, mold grows overnight, so garbage must be taken out immediately.
If you keep the farm in order, a full disinfection once a season is usually enough. This can be combined with small repairs during the summer break. Plastic air ducts should be replaced every two or three years.
⚠️And finally, a reminder: when working with chemicals always wear gloves, a respirator, and protective clothing. Even weak solutions can cause burns on the skin and irritation of the airways.
Emoji guide: 📌 link | ✅ advice | ▶️ fact | 💡 important | ⚠️ warning
