Conversation

They oyster mushrooms haven't turned out well. They're not supposed to look like this :(

The consensus among mushroom growers is that this is due to an excess of CO₂ in the fruiting tent. Mushrooms respire CO₂ as they grow, and they can essentially choke themselves on their own gasses in a closed environment. Oyster mushrooms are especially sensitive to this.

The traditional solution is to push lots of fresh air into the tent and/or vent the stale air out. There are a couple of problems with this, in my case:

1. I'm growing in a basement room, and my house is largely closed up for winter. This means elevated CO₂ in the ambient air. Pushing that into the tent might not help as much as real "fresh air" would. Soon, my only source of "fresh air" will be sub-zero.
2. Pushing fresh air drops the humidity, which is also an essential factor for proper growth, so my fight to keep CO₂ down will directly harm my fight to keep RH up.
3. I'm already pushing a gentle flow of air 24x7 with a small fan. Apparently this is not enough, possibly because of problem # 1.

So, I was thinking of experimenting with CO₂ scrubbing. If I can't get enough fresh air in to flush out the CO₂, maybe I can just remove the CO₂ from the standing air. Saltwater fish keepers already use small CO₂ scrubbers on the air intakes of their skimmers, to avoid dissolving atmospheric CO₂ into the water (thus lowering the pH due to the creation of carbonic acid). All that's required is a small canister of soda lime granules (as used by SCUBA and medical re-breathers) to cycle the air through.

Commercial units look like this, but it's really just a water filtration canister with a refillable insert. I can get that online for ~$25. So, I'm inclined to give it a try. The only thing that gives me pause is that I can't find much evidence that anyone else has tried this before, and there are people with much more intelligence and experience out there than I possess. If it's effective, I'd expect it to be a more commonplace solution. What do you guys think?

#mushrooms #fungi #carbondioxide #CO₂ #CO2 #saltwater #reefkeeping #corals #chemistry