Humidity in the grow room tent

No, not at all. At least not indoors, except in extreme cases. To monitor the growing environment, there are hygrometers with remote probes. These are the most practical, as they allow you to measure temperature and humidity at plant level. Personally, I put a second one in the air extractor, so I have an extra average volume. To raise the humidity level, there are quite a few inexpensive humidifier models that do the job well, it's up to you to decide what size tank you want. Keeping the water in the cups can also help if you don't want to take the humidifier out for a few extra percent. To lower the humidity level, you can use a dehumidifier. But be careful, there are a lot of gadgets out there. The most effective ones use a cooling system to catalyse the humidity. If it's hot, you can also use an air conditioner to dry out the air a little. If your extractor allows you to adjust the speed, you can also play around with it to adjust the level of humidity (but especially the heat).

Are you trying to raise it or lower it? Rising it is easy enough, you need a humidifier, I have used a electric one and I have also used wet towels in the tent to boost RH Lowering it is a bit harder, AC will bring RH down, so does a dehumidifier, about the only options I know, Good Luck!

lol, if you have issues now, have fun with large plants transpiring... :P Also, that isn't a question. A point of reference: 16sq ft of plants needs at least a 30pt dehum in order for it not to run 24/7. My 50pt in winter (furnace on, 30% RH normally) can barely keep up with 35-40sq ft garden, which is a bit more than double. Don't go cheap with a dehum. Buy larger than you need. Plants gas off a lot of moisture. I wish i had a 70pt in hindsight. (newer standards.. if labels from old standards that's; a 90pt -- can be confusing with 2 standards displayed depending on age of model.) humidifiers are simple -- A wick that soaks up water and increases surface area while a fan blows over it it can take care of large spaces without getting that nasty residul all over. avoid atomizers. The cool evaporative type are what you want. in an arid climate (furnace+winter) need these early then turn off as foliage produce enough humitiy on their own.