The $79 water spec

Last reviewed: September 12, 2026

The plant lookup is free and always will be. The spec is for people who want the math done for their house and written down in a form they can hand to a contractor.

What is in it

The plant band we used, named. If your address cannot be pinned to one plant, we say unknown and run the whole thing twice, once for each band, instead of guessing.

The grains per gallon range, taken from the city's published table and nowhere else.

The sizing formula, printed, with your numbers in it. Grains per day equals grains per gallon times people times 75 gallons. Capacity needed equals grains per day times days between regenerations, typically 3 to 4. You can check our arithmetic, and you should.

Valve guidance. We favor serviceable, widely available control valve families such as Clack and Fleck, for the simple reason that parts and service are not locked to one company. Proprietary stacks that only the selling dealer can service are a risk worth knowing about before you sign, not after.

A prefilter call. Consider one or skip one for your setup, with the chloramine reasoning explained rather than asserted.

Eight questions to ask any contractor who gives you a quote, written so you can read them straight off the page.

Optional product links, clearly labeled where they are affiliate links, so you can see typical equipment at typical prices. You are not required to use them and the spec does not change if you do not.

A link to license verified plumbers and water treatment specialists on this site. That list is not sorted by who paid, because nobody pays.

What it is not

It is not a lab test of your tap. We do not test water and we do not send anyone to your house.

It is not an installation quote. We do not install, and we do not take a cut from the person who does.

It is not a permanent number. The city updates its published data, so the spec carries the source date it was built from.

Price

The plant lookup is free.

The spec is $79, delivered as a PDF by email.

An annual refresh is $49if you want it rebuilt against the city's current published numbers. It is optional and nothing expires if you skip it.

Disclosure

Some product links in the spec and on this site are affiliate links. If you buy through one, we may earn a commission at no additional cost to you. Affiliate relationships do not affect which equipment we describe, the sizing math, or which providers appear in our directory.