FWIW, I've been using Zero Water filters for years and they live up to the name, although they are a bit pricey.
Of
course, choosing the best filter for your situation depends on what your working with & trying to achieve .....you may find this video of interest:
NOTE: The video tests for TDS only, there are other things to consider. In reading the comments for the video, viewers made the following remarks:
(comment by JacksonKnives)
The TDS test is basically meaningless unless you're comparing RO, distillation, and ion exchange filters. Most of these are carbon filters. ZeroWater is cool if you're specifically trying to get deionized water and only need small quantities, but for lots of people with hard water the filters exhaust quickly and it would be cheaper to buy distilled by the gallon.
(comment by DavidL)
Jackson is absolutely correct, TDS is meaningless, at least in the context of these tests. Each of these filters do different things for different reasons and cannot be compared. Its like saying a hack saw cuts better then a wood saw, but you are only cutting metal. That's true, but a wood saw cuts wood better. The zero filter using ION exchange and is used if you are say, filling an expresso machine and want to avoid calcium. A life straw is intended to filter out bacteria for emergency purposes and doesn't care about TDS. Charcoal filters do not impact TDS in any real way, They will lower it slightly, but they are not intended to lower it, and if they do, its coincidental. I have watched many of project farm videos and they are all fantastic, this is where i go for product tests. But this video needs to be flushed out more, no pun intended.