I recently made my own water filter, using commonly available parts. It is essentially a low-cost clone of one of the popular Berkey Water Filters. (Those are pictured above.)
The material list and sources for the parts for this water filter are below the description of its construction and use.
The base for this water filter construction is a 4-inch (inside diameter) Schedule 40 white PVC DWV pipe, cut 24 inches long. It is capped top and bottom but only the bottom cap is cemented on. Both caps have a ½” hole in the center. The hole in the bottom cap is for the filter outlet. The hole on the removable top is to prevent suction, a piece of cloth would do, in its place. The filter element is a white candle-style gravity-fed filter, such as used in the popular Berkey water filter. I use a British Berkefield Doulton filter, which is the same diameter and length. The stem goes through the bottom PVC cap and the unit is set on any container of sufficient size that can capture the filtered water. If you click on the photo of my prototype (at left), it will zoom up in size.
The simplest method is to put a gallon wide mouth jar inside of a 5 gallon bucket with a hole in the lid for the filter to pass. The size of the PVC pipe and the size of the filter are the correct sizes so that it holds one gallon of water at a time. A 2-quart pitcher is a convenient way of accurately filling it up.
The 4” diameter is large enough to get an arm in there to hold the filter in place when installing or removing it and narrow enough so that more of the surface of the filter is in the water. A larger diameter base would spread out the water so that the bottom section of the filter would be getting more use than the upper section. Every so often the filter can be removed and the surface scrubbed clean with a green scrub pad and reinstalled. They can last for years.
Material list with costs, as of October 2024:
1. 4 in. x 2 ft. PVC DWV Sch. 40 Pipe $17.86 (Home Depot)
2. PVC S&D Cap, 4 in. $3.67 (Home Depot)
3. 8 oz. Regular Clear PVC Cement $7.96 (For potable water) (Home Depot)
4. Wadoy Water filter compatible with Berkey gravity filter is $49.97 for 4 filters. (Amazon)
About the safety of PVC for use with drinking water:
The Architect Wisdom website asks: “Are PVC pipes safe for drinking water? Answer: PVC pipe has been proven by many European research labs to have excellent resistance to migration (when chemicals are leeched from the pipe into the water or vice versa) which means that it is excellent at preventing microbial growth and therefore low in risk of abnormal smell or taste.”
For Greater Capture Capacity
A five-gallon food-grade HDPE bucket can be used to store water for utilitarian usage. For drinking water, a food-grade material must be used. Such buckets will be marked “NSF” or “Food Grade”. Do not use 5-gallon paint or utility buckets, such as those sold by Home Depot and Lowes. A commonly-available water spigot can be attached by drilling a hole near the bottom of the bucket. The hole in the Gamma Seal spinner lid prevents a vacuum and also allows the filter bucket can be placed on top. A black bucket can be left out in the sun to help attain hot water, but it might take several days for that to happen.
JWR Adds:
For anyone that is not handy with tools, several of our advertisers and one of our writing contest prize donors sell British Berkefeld (“Berkey”) filters, constructed of stainless steel. Though they are fairly expensive, they are built to last a lifetime.
Read the full article here