For more information on storing, purifying and filtering water, see our post here.
Thank you to this site for the inspiration and instructions needed to make your own Berkey-type filter out of 2, 5-gallon, food-grade buckets. With the buckets acquired free from a local grocery store, our total cost of materials was $117, $107 (for a set of 2 Black Berkey Filter elements) and $10 for a spigot, both from www.jamesfilter.com.
What’s cool is that you can dismantle the whole thing and simply stack the buckets with the filters and the spigot inside. When the buckets are stacked, there’s enough room for the filters to fit inside the first one without the bottom of the next one hitting them. When you assemble make sure you tighten the spigot enough…I had a slow leak until I screwed it in tightly enough: grab the inner nut and turn the spigot itself around to get it tight. We take it camping and find that an extra bucket is helpful for filling the upper bucket of the assembled “Berkey”, especially since the rate of water filtration is fastest when the top bucket is full.
The dimensions of the finished product are 11.91″ dia. x 14.50″ high x 10.33″ dia. at the bottom. So, 2 buckets gives us approximate dimensions on homemade unit as 11.91 D x 29″ H and will store 5 gallons of water. This compares most closely with the Imperial Berkey because the storage receptacle holds 4.5 gallons (vs. 5 gallons for homemade) and because the heights and diameters are otherwise similar (see table below). Thus, we assume flow-rates will be similar for our homemade unit as the Berkey Imperial. In practice, the main control you have over the flow rate is how topped off you keep the upper bucket water. It is pretty slow so keeping the upper bucket as full as possible is helpful. I’ve noticed that when the water in the upper bucket is about 6 inches below the top, the filtration rate slows dramatically. Also, we assume we could put up to 6 filters into our homemade unit although our diameter is closer to Crown than Imperial (this would also increase the flow rate) AND we’re only storing 5 gallons instead of 6 which means that our top is perhaps similar in capacity to the Crown. So experimentation there would probably be worthwhile.