Lots of us have Vacu-Flush heads and other units that are sold as requiring less water than normal heads. This advise also apply’s to most newer electric heads. Believe that if you want to but read the owners manual to learn how to disassemble the unit. Your head and your nose will be a lot happier if you flush a good bit of water through it. At the end of each weekend or every few days, fill the bowl to the brim with water and let it all flush through. This will insure that gunk does not build up and make the inevitable head disassembly much less frequent.