How WaterSpec Lab makes money

By Andrew Bates, FounderPublished 2026-09-09Updated 2026-09-09

WaterSpec Lab earns affiliate commission when a reader buys a system through our links. It does not change which system we recommend. The sizing logic runs on your test numbers before any product is matched to it, and we publish that arithmetic so you can check it yourself.

What we earn

We participate in affiliate programs run by water treatment manufacturers. When a reader buys a system through one of our links, we receive a percentage of the sale. The reader pays the same price either way.

What that does and does not influence

It does not influence sizing. The System Finder maps your test results to a system class and a capacity figure using published standard scopes and manufacturer specifications. That calculation happens before any product is attached to it, and the arithmetic is shown on screen.

It does influence which brands we can recommend at all. We can only link to brands whose programs accepted us. Where a product we cannot earn on is the better fit, we say so and do not link it.

The concentration rule

We hold relationships with at least three paying brands and act when any single one exceeds half of revenue. A brand that supplies most of your income can change its terms unilaterally, and that pressure eventually shows up in the recommendations. Diversification is an editorial safeguard, not just a commercial one.

Where disclosure appears

On every page that recommends a product, above the first recommendation — not in the footer.

The bottom line

We earn commission on systems bought through our links, and that does not change which system the arithmetic recommends — sizing runs on your test numbers before any product is attached to it. What commission does change is which brands we can link at all, so where a product we cannot earn on fits better, we say so and do not link it. We hold at least three paying brands and act when one exceeds half of revenue. If that trade is not acceptable to you, use the method and buy anywhere you like.

Who this is not for

If you want a recommendation that ignores commercial relationships entirely, this is not that site — and no affiliate site is. What we offer instead is a published method you can audit and re-run against any product on the market.