“Berkey was having issues with the blacks.”
I got mine before that issue came up and I’m sure that was fixed (if it was ever valid) since it is the gold standard. Agencies that work in third world countries only use Berkeys so Berkey would have been all over that issue.
My son, as a director of documentary films, has been all over the world in truly arm pit places and uses the Berkey for his crew and has for over twenty years and none have ever gotten sick from water.
I got the Katadyns years ago before Berkeys were sold here. A Berkey takes out smaller impurities than the Katadyn. I had three Katadyns and this Christmas gave one of them to my sister-in-law who had nothing. I also gave her a WaterBob. They are sitting on the coast at Corpus Christi and a hurricane coming in there would surely destroy water and power. I gave her a good windup radio and solar light lantern and other items in the past.
Sounds like you have the filter issue covered then. I wouldn’t worry about the pool water.