Put the word out anyway. If your people are using Berkeys, they need to know about the defective filters. They need to know about it before the SHTF and they need them.
On threads about defective Berkey filters, I always see one or two people that say they have had theirs for years and never had a problem. They did the red food color test and it is fine.That’s fine. They have older filters, from before the defective ones were made. But a surprisingly large number test and find out that theirs is defective. Sometimes, like me they find out that ALL of their filters are defective.
If they have even one defective filter, that negates the purpose of having a filter in the first place. Especially, if, like me you are using surface water.
Berkey didn’t notify me of the defect, even though I bought my Berkey and 10 filters during the time period that they knew they were turning out defective filters. I was alerted by another poster, and I believe he saved my life. You can save the lives of your friends!
By chance, I found an old upright coffee urn at home that we had forgotten about. Took some measurements and then went online and bought some replacement filters for a Berkey from cheaperthandirt.com (search filters). Then I bought a stainless steel salad bar tub and lid that precisely fits into the top of my coffee urn...the bottom of the salad bar tub is somewhat conical so it wedges into the top of the urn very nicely.
I assembled it all and then ran the old food coloring test...it worked like a champ. Four filters and the stainless tub and lid...'bout $100.