There may be times when clear water is not available such as after a disaster including major flooding or when backpacking or canoeing into remote areas. Ceramic filters can filter out the turbid and muddy particulates in the water but those particles will quickly clog the ceramic filter. For the best performance from your ceramic filter it is best to start with clean/clear water first but how can you cheaply, quickly and easily do that?
It’s called ‘ALUM’ (Aluminum Sulfate) a safe powdered chemical commonly used for removing cloudiness in swimming pool water. It is also used in cooking, pickling and used in some types of baking powder. Note, ‘ALUM’ does not purify the water; it only removes the suspended particulates. You must filter the water through a ceramic filter before drinking.
How does ‘ALUM’ work?
Murky, muddy, cloudy or turbid lake or river water is caused by microscopic particles usually 1 micron or smaller that river currents keep stirred up. Gravity has little effect on them because they are too small to have enough weight to settle out by themselves. These tiny particles have a negative electrical charge that prevents them from being attracted to one another thereby prevents their clumping into a heavier particle that will eventually have enough weight to sink by themselves.
When ‘ALUM’ is added to the water it neutralizes the electrical charge of these small particles and then these small particles will begin to clump together, become heavy and sink to the bottom. This process is called flocculation also called coagulation.
How to use ‘ALUM’ to clarify water:
1. Add a heaping ½ teaspoon of ‘ALUM’ powder per gallon of water (1 tablespoon for 5 gallons of water).
2. Stir for about 10 seconds to dissolve the ‘ALUM’ and in about five minutes stir again.
3. Wait for 1-2 hours and the water will be clear and ready to pass through your ceramic filter. Just dip the water out or carefully pour the water out and into your ceramic filter. That’s it!
Where can you buy Alum?
You probably already have some in you spice rack.
Supermarkets sell it in the spice section, although it is very expensive at $3.00 for 2 ounces.
Any online bulk spice retailer such as:
5 pounds will clarify 630 gallons of water or 126, 5 gallon buckets of water.
Search the web for other retailers, there are many to choose from. Just be sure you purchase food grade ALUM and not an industrial grade that may have other chemicals added to it. The swimming pool industry uses ALUM to clear up pool water and it could have additional agents in it. This is why I buy it from spice companies.
ALUM from the supermarket. A 1.9 oz jar is expensive at $3.00 but will clarify 15 gallons of water (3 tablespoons in 1.9 oz).
Since I don’t have turbid water close by for the test water I scooped up some dirt from my yard and mixed and the ALUM into a gallon of water.