Fluoride measurement

[Beets]

Many years ago, the fluoride in well water was measured to be 5.9 mg/L which is almost 4 times the recommended limit for drinking. I use reverse osmosis for drinking water. I have never measured the fluoride after the RO. Are there fluoride test kits? I do have a TDS meter, and I know the TDS going into the RO is 320 mg/L and the TDS coming out is 19 mg/L. How confident can I be that the fluoride concentrations are going to be low enough that they will no longer be a problem?

Does anyone know of a activated carbon that is great for removing H2S AND fluoride? I have a H2S problem and I use centaur carbon. Wondering if there is a product that does both? Maybe I could eliminate the RO system.

 

[Reach4]

I would not have expected RO to be effective against fluoride, but I appear to be wrong. My logic was that fluorides would be disassociated into fluorine ions, and the atomic weight of that is about the same as a water molecule. I appear to have been wrong in my expectations.

In looking around, I found https://truthaboutfluoride.com/does-reverse-osmosis-remove-fluoride/
I tend to be suspicious of such sites who publish reviews to promote products. This one seems better than usual sites. One thing that stood out is they showed a fluoride meter. http://www.extech.com/products/resources/FL700_UM-en.pdf appears to be available for US$196 to US$300. https://www.zoro.com/extech-waterproof-fluoride-meter-display-lcd-fl700/i/G5041836/feature-product
https://www.testequipmentdepot.com/...ters/waterproof-fluoride-meter-9ppm-fl700.htm
I have used Zoro, and they are good.

On the Centaur Carbon system, how is that working. My H2S+Iron system regenerates the Centaur Carbon every 3 days with a chlorine bleach solution, and I use a gallon of bleach every 33 days.

 

[Sponsor]

 

[Bannerman]

Activated Carbon media is not recommended for fluoride removal, but some amount of reduction will typically occur.

Fluoride molecules are larger than water molecules and should therefore not pass through RO membrane. That said, reports are typically cautious to state RO will reduce any contaminant 100% so the usual indication for fluoride is 85-92% reduction.

Filter media often utilized specially for fluoride reduction include Activated Alumina and Bone Char.

Those types of media tend to be expensive and require frequent replacement. As significant contact time is required for effective reduction/removal, either a large quantity of media will be required, or the flow rate will need to be very low so as to provide the required contact time.

RO has become the preferred method for effective and low cost fluoride reduction for residential drinking water applications.

 

[Beets]

Thank you for the research on fluoride! I thought all RO's removed fluoride, so I found his article very interesting. It sounds like I really should be spending some money to test residual fluoride. Yikes, I had no idea. My kids teeth aren't blotching, so probably OK. I would be curious if anyone else has found a way to measure fluoride as the meters you found are fairly pricey.

I REALLY like the Centaur Carbon for H2S removal. My raw water smells like sewage, but when the water is treated, there is no smell. We drink it. We typically drink the RO water which has additional filtration, but our normal tap water has no taste or smell; we know it has high fluoride or we wouldn't bother with RO. The biggest challenge is that the centaur carbon requires oxygenated water. Initially, we had some sort of venturi device that sucked air into the line when the pump from the well was running. That worked well, but it didn't kill the sulfide reducing bacteria and they slimed the carbon up such that the carbon did not work for very long (several months if memory is correct). For the next 15 years or so, we added chlorine. That controlled the SRB's, and provided oxygen source for the Centaur to work. However, we had issues when the chlorine was old and lost its potency, accidentally ran out, or pump quit. If you didn't catch it quick enough, the SRB's would get established and would slime the carbon when we reintroduced the chlorine. We were using about 12 to 16 gallons per year of 12% sodium hypochlorite. For the last year or two, I've been adding hydrogen peroxide. It controls the SRB's and adds oxygen for the centaur to work. I think it's my favorite so far. A 69 kg drum of food grade 35% H2O2 lasts a year. Back wash every 6 days regardless of whether it was chlorine or H2O2.

 

[Reach4]

https://terrylove.com/forums/index....izing-extra-attention-to-4-inch-casing.65845/ is my well and plumbing sanitizing article. August/September would be a good time. January/February would not.