I tried to post a reply but somthing messed up..Very bad assumption to make that 220 could ever be safer than 110. It is all about Ohms law V=IR. It is the current that will kill you! 220 will push twice the current through an impeadence than 110.
Yes a machine on 220 will pull half the current for given power output than 110, but will still pull the same amount of power! The real reason for going to 220 would be to reduce the physical size and wieght of a particular machine, can have a reduced size and weight of a motor or machine at a higher voltage than at a lower voltage, but who cares!!!!
Realy what you want to do is go from 110 to a step down transformer and 24V to your airator this makes the most sense and is safest!
But please please don't fool around with 220 and water it is deadly!!!!please dont............
