Thanks for the great info. Sent quote request--Malibu Water "these windmills can only be mounted on a tower"--Stone Creek Inc "use 4" pipe and weld bracket on top to mount windmill head" quoted two windmill less towers with membrane difuser $1642--Superior Windmill has not replied--Joe Mescan Windmills has not replied-- I will purchase 2 shortly and if they work ok will get 2 more.