Right on. Here you go (I’ve run a similar tent for a couple of years):
Move the humidifier outside of the tent and pipe the humidified air in. This will drastically increase the lifespan of your humidifier (there are electrical components inside which will corrode and fail very quickly in high humidity). It’ll also make it easier to refill the reservoir without having to open the tent. You’ll have to improvise the piping; I’ve used swimming pool pipe to good effect (you want something that’s flexible and easy to clean).
You’ll need to reinforce a section of the plastic tent where the pipe enters; you can do this by creating a rectangle with a few layers of duct tape (the idea is to prevent the plastic from tearing). I like to place this entry point on the side, at roughly the level of the first shelf (you could also place it on one of the slanted ‘roof’ sections). The humidified air will fall downward as it leaves the pipe.
Depending on the species you’re growing, you will very-likely need more airflow. With oysters (Pleurotus spp.) you can probably get away with simply leaving both door-zippers unzipped and running an oscillating fan in your room. A species like Hericium erinaceus prefers more fresh-air exchange (FAE) so you will either have to pipe fresh air in or modify your tent. I got excellent results by making a grid of small holes over the entire surface of the plastic cover. The downside to that approach is having to melt plastic…not fun (if you do this, do it outside).
Um…what else…watch out for mold growth on the inside of the tent. You’ll need to clean at least once a week when it’s in full-swing. If you ever start seeing weird growth in your mushrooms, it’s probably the result of a contaminant that you’re not seeing.
Be aware that the shelves are going to rust. There’s no real way I know of to prevent this. This is why stainless steel is ultimately the way to go. That being said, the tent you have will serve its purpose for the time being. You can always level-up to a cannabis-style grow tent and stainless steel shelves at a later time.
You might already be doing this but it can be helpful to run the humidifier on an timer. That will give you a lot of control in order to dial-in your setup. For example, you might find that running the humidifier at 1/4 “power” for 15 minutes every hour is just-right.
I hope that’s of some use!