Humidifier

Don't bother. The rapid air exchange most tents have to keep cool from the hot lamp don't let a humidifier do anything. It'll only do any real good in a sealed space with no outside air coming in.
I grow in low humidity all the time and it dosen't slow the plants at all IME
BNW

 

If you can get a humidity controller that would be ideal.

You can spray the inside walls of the temp a couple times a day to increase

 

I've bought about a dozen humidifiers.
The best, and most expensive, are the top fill ultrasonic humidifiers, and they can keep humidity pretty high, even with an exhaust fan.

This is a decent one that holds 1.5 gal:


Here's a cheaper, smaller one:


I haven't yet found a top fill ultrasonic that disperses its mist very well, so I use a separate fan to blow it around if possible.

It's also possible to buy only the ultrasonic vibration unit, and then it's called a fogger.
The cheaper bottom fill types are a hassle to fill, and the evaporative types that just blow air over wet filters can't get the humidity very high.

I keep humidity in my in the mid 60s all the time, even during flower, while following the vapor pressure deficit chart.
When far enough into flower, plant transpiration will do most of the humidification.

 

Forgot to mention that the ultrasonic ones must use RO or distilled water, or the impurities will spew out and become white dust after drying.

 

I bought a levoit 4 liter on amazon for $35 bucks. It has a pretty blue light. Very good purchase for me. Weed gets so dry here in the winter you can't even roll it or it will rip the paper.

 

Once your plants get bigger, your humidity will increase. Trust me.