COLLOIDAL CLAY IN YOUR WELL WATER?
We run across our fair share of folks living out in the country who have had this problem. This source of aggravation is easy to fix, due to the advances in water treatment technology. Here’s the problem with this type of clay – it is suspended in the well water (very tiny particles), which means it doesn’t settle out. We call this colloidal clay, just in case you’re interested. “Just how tiny are these particles?”, you might ask. Less than one micron in size – that’s plenty small- much smaller than one of those red blood cells we learned about in high school health class.
You’ve got two ways to rid yourself of this problem. The first way is to get the particles to stick together to form bigger particles (clumps of clay). We call this process of small particles sticking together coagulation. It takes an addition of a chemical to the well water to form the clumps which, by the way, are now about the size of one of these red blood cells after coagulation. One chemical compound usually added to the well water is called alum (aluminium sulfate). These clumps of clay can now be removed from the water, using a filter that can handle particles that are around 5 microns (or greater) in size.
The second way to eliminate the clay without adding any chemicals is to use a filter specially designed to remove submicron (i.e. less than a micron) particles. This approach uses an ultrafiltration filter. Ultrafiltration filters are capable of removing particles ranging in size from around 0.002 microns to 0.1 (one tenth the size of a micron). When the ultrafilter starts to fill up with these tiny pieces of clay, it will be cleaned using a process called backwashing to extend the life of the filter. The filter is backwashed with clean water to dislodge the unwanted particles and flush them down the drain. We prefer this second approach because less equipment is required (no holding tank(s)) thereby saving space, and no chemicals are required (more environmentally friendly).
— By Steven G. Karr PhD