Adam I. Gerard

Water Purity

Some concerns about home water purity and solutions.


I got introduced to the importance of water purity from my interest in reef-keeping. Marine ocean water is a complex mixture of various chemicals (not just salt) like ammonia, iodine, calcium, phosphates, nitrates, nitrites, etc.

House-hold tap-water is impure and needs to be filtered (and chlorine removed) to keep marine life healthy.

Most reef-aquarists use six-stage RO/DI filtration designed specifically for marine aquariums (most really good human filters are effective only to 99% whereas most marine filters are effective to 99.999%).

Those lessons underscored the importance of good water purity and the impact even slight fluctuations in water chemistry can have on biological systems!

Poison in US Fluids

America has a disturbing water lead problem and water infrastructure crisis:


Even in common fruit drinks!


Impurities like lead can cause significant brain damage over time (mental degradation).

I’ve argued elsewhere that most differences in IQ stem not from genetics but from choices surrounding diet, education, and the correct application of science toward human problems.

It’s tremendously disheartening to think that public utilities are failing to provide quality services to America’s tax payers and their customers. Even many second-world countries do better and almost all first-world countries do.

Clean Water

For water - you should:

  1. Filter it
  2. Boil it

You have to do both. Filtering only removes heavy metals and chlorine. Boiling it only removes bacteria or other biological compounds missed when filtering.

I use these:

  1. (any will do - I finally splurged and got one of these).
  2. under kitchen and bathroom sinks.
  3. for my shower.

I’d also recommend:

I prefer “whole-house” solutions rather than a “pitcher” since every water scenario is improved: pets, showering, baths, lawn, cooking, tea, coffee, hand-washing, etc. You don’t have to refill these or prepare some stockpile. They typically last a year or more.

Check out this great blog post comparing common water filter brands:

Bottled Water and Its Limits

Otherwise you can drink bottled water instead.

Obviously this gets expensive and only modifies what you drink (and not what you cook or shower with).

For bottled water, I generally recommend FIJI (despite its cost or some local RO/DI (many grocery stores have bottled water stations where you can bring your own jug and fill it up).

I say this because many bottled water companies only use local tap water (giving you no benefit).