Observed arrival · 2026-08-30
水槽ものさし: The Aquarium Water Calculator
A Japanese calculator for estimating an aquarium’s actual water volume, heater size, filter flow, and water-change amount.
Field notes
The calculator separates external tank dimensions from the water actually available to livestock, subtracting glass, headroom, substrate displacement, and hardscape while optionally adding filter and hose water. Its standard-size table covers ten formats, including 30cm cube, 60cm wide, 90cm, and 120cm tanks. Heater estimates incorporate temperature difference and whether a lid is present; the page also exposes porosity and hardscape volume as direct inputs when its defaults are not suitable.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
One card from the complete issue