Calgon is a brand now used by several different companies for a wide range of products. The original powdered water softener with that brand name was sodium hexametaphosphate. This is not the current formula for the Calgon-branded water softener, since the EPA banned the use of phosphates in many consumer products. But you can still buy sodium hexametaphosphate as an industrial product. Calgon dishwasher detergent is not the same thing as Calgon water softener, nor is the liquid the same as the powder.
I use the combination of Borax and (non-phosphate) powdered detergent for my GEO method. Washing soda (disodium carbonate) might work just as well.
The function of Calgon water softener products is to bind calcium ions in hard water, so they don't interfere with the action of soap (pretty much no longer used in the laundry) or certain types of detergents. Borax and washing soda have the same function. Most detergent formulas already include one or more "softening" agents. So not finding Calgon will not keep you from successfully using the GEO method, particularly if you are not dealing with "hard" water; the detergent is often enough.
In bulk, or even in larger consumer packages, borax is a lot cheaper than the Calgon softeners and does double duty as an insect control, particularly ants.
Tom Test
Itasca Spirit 29B
