When used in a large apartment is enough. I found under the bed a bunch of all sorts of nonsense stuffed there by children - that I didn’t in, I pulled it out)))) In principle, a tank of water is enough, do not expect a full-fledged washing of the floor - it is not a mop. But every day it’s a little wet to wipe the dust very much, especially if you don’t have to do anything for this)) There are a lot of spare parts included, if necessary, buying on the market is not a problem and very inexpensive. There is a charging function not from the station but directly (convenient and useful for emergency situations). In general, everyone is happy, except for cats =)))