Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: How many gallons of water does this hold?  Thank you
Document: Doesn't hold enough water to last the night on full; that's the only drawback.
This works very nicely. I got it for a bedroom that I sleep in because I was getting a nosebleed from the dry heat in the house. It has a nice easy adjustment knob. Hold plenty of water and is for the most part quite. It did the job.
There's no way to get a firm grip on it for when you need to refill it. It does have a sort of recess in the back, but it's not very sturdy, and isn't big enough to get a hold on to anyway. When the tank is full, it's difficult to carry. I'd estimate the tank has a capacity of around 3-4 liters of water, which makes it heavy enough that it's awkward to carry clutched to your chest, but unfortunately that's the only way to really do it.
Works OK but SOAKS anything absorbent that is nearby. I've never had this happen with a humidifier. I think some people might think &#34;then you know its working&#34; but I also think that the density of the water vapor keeps it from adding moisture to the air.The noise isn't an issue for me as I see many reviews complain about it.
Works well and puts a quite a bit of moisture in the air. Suitable for a bedroom. Floor in front can get moist so I put down a large plastic bag. My unit has not leaked as many other reviewers have reported but I have only had it about a month. I use distilled water and clean weekly. I would have given this 5 stars except I find it awkward ti refill.
Thank You came in record time! Works great and is quiet.
Easy to use, not very noisy! Fair price! I like it ! I also recommend this for you! Thank you!
Our gas heater sucks the moisture out of our home, this humidifier changed the air in our house instantly. Our sinuses thank you.
Works as well as the more expensive models. Easy to clean. When refilling be careful. It's hard to hold onto and I broke one, but at this price, it isn't a disaster. I just bought another one.
This is my least fave humidifier so far and I go through ALOT of them. Doesn't hold much. Messy to fill. Hard to clean well. Pools on floor. Keep running  in sink at night.
Answer: about 3/4 of a gallon of water (I buy distilled water by the gallon), it will run on lowest for several days without refill.