Dwight, Thanks for that post and always sorry to read those tragic stories. Windmill type aerators will generally keep ice thin in the approximate area of the diffuser until they open the ice but this should not be taken for granted. It is so easy to forget about the windmill doing its job when you have a complete iceover.When open water in not wanted or needed please consider a simple bypass valve in the windmill airline to allow the ice to become thick while the exhaust is vented to the atmosphere.When opening thick ice with an electric unit keep in mind that prior to ice opening the water and air bubbles can and will "trail off" many hundreds of feet in an unpredictable direction(s)thus making a pond or lake of any size potentially unsafe.Even if you have moved a diffuser in a shallow area as a dedicated winter diffuser be aware that thin ice can be in other areas. Also consider posting "WINTER AERATION caution THIN ICE" or something along those lines.
