The Waterline is an editorial publication about aquariums and fishkeeping. It is for curious beginners and experienced keepers who want to understand the choices that shape a tank, without treating every setup as if it were the same.
What we cover
Coverage follows the parts of an aquarium that depend on one another: tank design, water conditions, equipment, aquatic plants, and fish behavior. Subjects range from planning a layout to making sense of a filter or noticing what a change in fish behavior might prompt you to check.
Who it is for
The Waterline is for people planning a first aquarium, adjusting an established setup, or looking more carefully at how their tank works. We explain terms as they arise and keep recommendations tied to the situation being discussed rather than presenting one setup as right for every keeper.
How we approach it
We favor clear explanations, visible checks, and manageable steps. A water test is a reading to interpret; a piece of equipment has a specific job; and a change to a tank deserves attention to what else it may affect. When a question depends on species, conditions, or local rules, we say so rather than smoothing away the difference.