A friend of mine sent me pictures of his PF cakes (2:1:1 verm:BRF:water recipe)

The cakes sit on wet perlite while one cake is look suspiciously fuzzy. We are not sure whether this is mycelium or some fluffy mold. The smell test is inconclusive.

Second picture shows the cake after jar has been opened. The white organism broke through the layer of vermiculite to the very top also giving a suspicion of mold.

Any suggestions?

Whit those blurry pictures its hard to tell.

My mycelium was hella fluffy too but it was clean with perfect smell and quick pinning.

It could be a reaction that there was some small contaminant that made the myc fluff up.

Looks like fluffy mycelium to me. Sometimes, there will be a pin at the peak of one of these hills. Perhaps more fanning could help. I had this before during the colonisation process even with very little gas exchange.

Thanks. So I'll advice to fan more and use better camera next time

this is said to be caused by bacteria.. i had it on my first grow when i put my cakes into a fish tank, once i moved them into a better fruiting chamber the growth stopped and i had pinzzz. what kind of fruiting chamber is your friend using? fanning won't help but increasing fresh air exchange will.. i can see a bag, put some holes into it

He uses the standard spawn bag with micropore filter.

I will therefore tell him to make holes.

It is interesting that purchased growboxes need no air exchange (just the filter), there is no bottom CO2 venting and the mushrooms grow just fine, yet the PF cakes need much more FAE. Why is that?

Do they always grow fine? well sometimes they do, but i frequently see people suffering with this setup called "the choke bag" on the shroomery and the solution is to either make holes or build a SGFC. there's a lot of factors and to leave just a little room for chance it's better we follow the methods

Once I tried to do a montotub without any of the double row air exchange stuffed holes. Things seemed ok at first, but the micelium stalled half way through. I gave it extra time out of curiosity, but it had just stopped.

The way I understand it is that micelium needs to breathe O2 just like us, and more micelium needs to breathe more. This means enough FAE which depends of the micelium volume.

Pre-made designs are made so there is enough O2. Home made/new designs may work one day, but if you add more micelium mass, issues due to not enough FAE may show up.

It's like a bunch of people stuck in a tight space with little FAE. One or two people may survive, but keep on adding people and at one point they will start dying. So again, you have a max biomass for a certain FAE. In the poor monotub FAE experiment above I think the micelium grew as big as it could and then understood that it had to stop due to the poor FAE.

Now I put monotubs atop of plants so the CO2 the micelium exhales cascades on them, just for fun.

Oh, and as you all may know maximizing O2 may not be ideal either. Some claim that to fruit, lower O2 levels give the best result. That could be why the momotub is so sweet: Fixed FAE through stuffed holes means that as colonization reaches 100% O2 levels drop just in time for fruiting. You can get different size fruits as the mushrooms reach up to find more O2.

These are just my musings, not facts. One day I may get an O2/CO2 sensor to try to observe this effect. Not just for curiosity, folks publish ideal CO2 levels for fruiting, so using g the sensor as feedback the number of FAE holes can be adjusted so by the time colonization is 100% the CO2 level is ideal. And this optimization should be for a fixed substrate mass.

All this is hypothetical until it can be tested with the O2/CO2 sensor.

I grew about 8 boxes from different vendors and they all explicitly say to close the bag and never touch it until harvest.

I found however my grows were quite tall (7-10 cm). I though this is normal but the srooms were probably reaching for oxygen. My SGFC consistently produce 4-6 cm long fruits - I first thought they are small but after seeing lots of photos from The Psilocybin Mushroom Bible, it seems to be the norm.

So I will advice a friend to punch few holes. He wanted to just open the bag occassionaly, but that obviously won't help unless he actively vent the carbon dioxide.



Willy Myco did exactly that in one of his monotub videos (don't have time to search it now) to show one needs not to be too crazy about FAE. There was some CO2 increase after a day, but simply opening the lid and giving in a good whiff returned CO2 level to normal.

So things like holes everywhere and fanning 6 times a day is surely unnecessary, not sure where the other extreme lays.

Thanks blue.magic, did not know of that experiment. Was the CO2 sensor used to Target the monotub design so optimal gas levels would be reached at full colonization?

He just measured CO2 level in a 12 hour interval and shown the level raised only negligible. Unfortunately I am unable to find the very specific video of this.