Koenders Windmill Replacement Parts Biofilter The nominal wall thickness is

The nominal wall thickness is between 3/16” and 1/4” making a nice sturdy tank

and one 7" aluminum oxide air stone with check valve

5” FNPT inlet and 1

and other recreational uses are approved during and following the use of this product

improving the overall water quality

Koenders Windmill Replacement Parts Biofilter The nominal wall thickness isReplacement parts for your existing Koenders Windmill Windmills that were purchased before the year 2000 will be a generation 1 unit, and require "old style" parts. Any unit purchased after the year 2000 will be a Generation 2 or newer. Most parts are interchangeable for single and double diaphragm units, though double diaphragm units require the 26" blades and 2 diaphragm repair kits.