govee humidifier and matching humidity/temp reader. I use this combo in all my ikea greenhouses.
humidifier only $60 on amazon. its small enough to not take up much space and bluetooth with their app. https://www.amazon.com/Govee-Humidifiers-Bedroom-Essential-Humidifier/dp/B098PBQP1K?pldnSite=1
and the matching sensor to control the humidifier automatically.
So the humidifier pairs with a sensors, Govee has wifi and Bluetooth ones, either will work. Wifi you can check remotely, but I have a spare phone with Teamviewer set up, so I check it that way. This is nice because you can set the sensor anywhere in the tent and not rely on the air at the bottom like with built-in hygrometers. They are also very accurate and consistent.
The rest of the stuff is standard 1/4" plumbing parts with push fittings you can find on Amazon.
So the humidifier is the Govee 4L, It will hook up to your Wi-Fi so that you can control it remotely, you can also pair it with one of their hygrometers either their Bluetooth or Wi-Fi versions, and use that to control it and set the humidity anywhere between zero and 75%. That tank above is the RO water tank that I use for watering my plants, and it is hooked up to the same RO filter that is feeding the humidifiers.
The overall system is pretty simple, it uses a mechanical float valve to shut the water off when the tank gets full, and there is a special four-way valve that also shuts off the wastewater so that it doesn't continuously run after the tank is full. That garden hose going out of the back of the tank is an overflow line. Basically that runs to a drain, and the wastewater line is tucked down that hose as well so that it just runs to sewer.
One cool thing about this kind of a setup is that now that I have my drain line all set up, I can simply tee off of the supply line, and feed multiple things like humidifiers or a water tank for a hydroponic setup, etc.
Water Filter Float Ball Valve 1/4
APEC Water Systems Auto Shut Off
The auto shut off valve is kind of the heart of everything, it's purely mechanical and it allows you to supply everything with one valve basically, however, I would always recommend that you have an overflow solution ready like either a catch pan with a drain, or like I have in my tank where if it overfills it simply runs down to the drain line.