About Gallons and Fins

Gallons and Fins helps freshwater aquarium keepers with the numbers: how much water is really in the tank, how big a water change needs to be, how much of an ammonia reading is the toxic form, and how much of a treatment to add. Our guides explain the water chemistry using university extension and government sources.

Who runs the site

Gallons and Fins is a small independent website run by the Gallons and Fins editorial team. We are not a manufacturer, retailer, government agency or professional service, and nobody pays us to feature a product or brand. The site launched on Nov 11, 2026.

We do not put names, job titles or credentials on our pages that we cannot back up. Instead, every page shows what it is based on: the formula behind each calculator and a list of the official or reputable sources we checked, with the date we checked them.

How the tools work

Every calculator runs in your browser. Nothing you type is sent to us. Trackers and logs save to your own device (your browser's local storage), so they stay private and disappear if you clear your browser data. There are no accounts.

How the site is paid for

We plan to support the site with advertising in the future. No ads are shown yet.

Some guides contain a small number of clearly marked links to Amazon search results. As an Amazon Associate I earn from qualifying purchases. See our affiliate disclosure.

Get in touch

Corrections and suggestions are welcome on our contact page. Read how we check facts for our standards.