Neurons and Exercise

Neurons and Exercise

Monday, December 7, 2020

Fluoride Filter: How to make your own


Appendix VI – Bone Char Filter Construction

In order to filter the maximal amount of fluoride and arsenic from tap water or Silicade, the water must be adjusted to pH 4.8 with sodium bisulfate and then filtered slowly (i.e. less than 400cc/min) through a bone char filled filter cartridge and finally brought to pH 6.5 with sodium bicarbonate prior to drinking. The flow should be bottom-to-top in order to flush most of the air out of the bone char. The least expensive and most convenient way of constructing such a filter is to purchase an Aquatic Life ion exchange cartridge filter with quarter inch polyethylene tubing from Amazon. Pour out the ion exchange resin and fill the empty filter cartridge with bone char. The filter can be held vertically with two clamps attached to a lab stand (see figure 37).  More details are given below.


Figure 37 – Removing fluoride and arsenic from one gallon of pH 4.8 tap water or Silicade being syphoned through a bone char filter in series with a gravity-fed Brita pitcher style filter

Cut the polyethylene tubing into two different lengths and attach as indicated in figure 37. Use the Brita filter and plastic insert sold with a Brita pitcher style filter to catch the water flowing out of the bone char filter. Use two, one gallon-sized plastic or glass containers. In order to maintain the syphon, one container must be placed on a shelve that is higher than the exit of the outflow tube on the bone char filter (see figure 37). The other container must be topped with the Brita filter and be low enough to catch the outflow of the bone char filter. Start the syphon by sucking on the outflow tube on the bone char filter until water begins to flow. 

How to Prepare and Refill the Bone Char Filter

1.      Remove the threaded end-cap from the Aqua Life filter cartridge and if new, pour out the resin for disposal or if used, pour out the spent bone char for disposal while retaining the o-ring, plastic disk, and two particle filters (i.e. top and bottom particle filters).

2.      Rinse the empty filter cartridge and refill it with first the bottom particle filter and then the bone char until the top particle filter sets gently on the bone char and the plastic disk on top is flush with the top of the cartridge.

3.      Slide the o-ring on just above the cartridge threads and screw on the top cap being careful to not cross threads.

4.      Prepare pH 4.8 tap water or Silcade with sodium bisulfate microprills from Loud Wolf sold by Amazon.  Use a temperature compensated pH meter ($10-$20 from Amazon) and a set of Norpro measuring spoons, including “dash” and “drop”. Try starting with one level “dash” of sodium bisulfate with stirring per gallon and, if insufficient to lower to pH to 4.8, try adding one level “drop” of sodium bisulfate with stirring at a time.

5.      Syphon one gallon of pH 4.8 tap water or Silicade through the filter flushing the filter and then leave the filter filled with the pH 4.8 tap water or Silicade to soak the bone char for three days prior to use as a fluoride and arsenic filter. 

Bone Char Filter Performance

This bone char filter will remove 72% of fluoride from 50 gallons of tap water or Silicade containing 0.5ppm fluoride resulting in tap water or Silicade with only 0.14ppm of fluoride. With distilled water containing 1 ppm fluoride, 100% and 92% of the fluoride is removed after 25 and 50 gallons of tap water has been filtered, respectively. The fluoride capacity of this filter is 200mcg of fluoride per gram of bone char in tap water or Silicade.

After filtering 50 gallons of tap water or Silicade the bone char must be refilled. After filtering 75 gallons of tap water or Silicade, the bone char filter only removed 21% of the fluoride595.

This bone char filter will also remove approximately 60% of arsenic reducing arsenic levels to below 10mcg/liter (10ppb)603 the maximum contaminant level (MCL) of arsenic in drinking water in the U.S.   

Details on Components of Bone Char Filter

·         Bone char 20x60 mesh size can purchased in 6, 10, 25 and 50 lb. amounts from Charcoal House in Crawford, NE.  6 lbs. sells for $49.39 plus $20 shipping in a gallon jar SKU C-541. Density of this bone char is 1.089gr/cc and is $7.90 for a refill of this bone char filter. Call Charcoal House at 308-665-1566 as it is not available online.

·         Aquatic Life DI color changing mixed bed filter cartridge 2x2x12 inches with ¼” tubing fittings and 284cc internal volume (1.625” dia, x 8.375” = 17.36 cubic inches) for holding approximately 309grams (0.68 lbs.) of bone char. The cartridge can be purchased from Amazon for approximately $20 and it will be shipped free by Premium Aquatics. After receiving filter, empty and refill with bone char.

·         Polyethylene tubing ¼ inch NSF certified for food use from PureSec/CCK 100 feet sold by Amazon  for approximately $20.

·         Cast iron ring stand with acid resistant finish from American Educational Products sold by Amazon for approximately $20.

·         Two 3-prong lab clamps finger style from OESS sold by Amazon $13.45 each

Optional Suppliers of Bone Char

·         Bone char 20x60 mesh size made at 800oC can be purchased in bulk from Ebonex Corporation in Melvindale, MI, U.S.A. 313-388-0060 Cost per pound is $3.95 for the minimum order of a 50lb. bag not including UPS shipping (for a list of international distributors see:

·         Bone char 20x60 mesh size (e.g. 0.010” to 0.033”) can be purchased online by the pound at Highwater Filters for $16/lb. (Kosher/ANSI 61 Certified). Highwater Filters is in Colville, WA at 509-685-0933 Highwater Filters purchase their bone char from the Charcoal House.