The more flow you have, the faster you will clean. That is everything from houses to decks to concrete. We have zero problems running 10 gpm machine on a residential with a 110 gallon reserve tank. You can run into issues with well water or if your municipal supply is 5 gpm or less. Running a portable machine directly off a water supply is where you will get into trouble. Its best to have a buffer tank for a whole bunch of reasons.