I would recommend getting a fish tank air pump (I got a 2000cc one at Walmart for around $10) and leave that on in your chamber. Or you can do as Pup and Paulsage suggested and add way more holes, but you still may be required to fan. In fact, even with my air pump running, I tend to fan out my chamber once or twice, even three times a day.
Another thing I noted too is instead of perlite, I am using the expanded clay pellets that you can use in hydroponics setup and they have worked great so far. The added benefit to this is I believe you can sterilize them in the oven or PC, but have not tried that yet whereas with perlite, you'll need to change it out after every fruiting operation.
My cakes took about 8 days before I was seeing any signs of pinning. The chamber is fairly small, so FAE is no issue. The expanded clay pellets take up about 2 inches of the bottom, with distilled water with a little hydrogen peroxide added to help combat any waterborne contaminants.
I'll include a pic here soon to show my example that seems to have been working. Also one more thing, while 75* F is definitely recommended, it is not uncommon for my place to drop down to 60 - 65* F during the day while I am at work and from what I can tell, they seem fine with this temperature range. Also, you mentioned that your myc is white and fluffy? It is definitely supposed to be a whitish color, but fluffy isn't really ideal, you want thick, strand-y mycelium, where it kinda looks like some kind of creature that is "grabbing" your cake with little white fingers of goodness. Fluffy tends to not produce the best fruits from what I have read so far.
Keep us posted on how it goes!
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