Frequently Asked Questions
What is a typical water tank capacity range for robot vacuums?
Most robot vacuums have water tanks ranging from 200ml (about the size of a teacup) to 750ml (roughly a water bottle).
How does water tank capacity affect cleaning?
The bigger the tank, the more water it can carry and the longer it can run before needing a refill. A small 200ml tank might only clean one or two rooms, while a 750ml tank could clean an entire ground floor without refilling.
What happens if the water tank is too small for your home?
If you have a small flat with hard flooring and a 200ml tank, your robot might need to return home three or four times during a single cleaning session, leading to more stops and longer overall cleaning time.
What are the alternatives to a robot vacuum with a large water tank?
The alternatives are accepting you’ll refill more often, choosing a vacuum that doesn’t mop at all and sticking with traditional mopping, or using a robot that has a very small tank designed for light spot-cleaning rather than proper mopping.
The bottom line
Water tank capacity is a practical feature that’s worth considering if you want your robot vacuum to also mop your floors without constant refilling interruptions. For small homes or occasional spot-cleaning, a 300ml tank is perfectly adequate. For larger homes or those who want a proper mopping experience, aim for 500ml or higher. But remember: this feature only matters if you actually want a mopping vacuum. If you primarily need dust and debris removal, save your money and get a dedicated dry vacuum instead. The best tank capacity for you is the one that matches your actual home size and cleaning habits, not just the biggest number on the spec sheet.