Observed arrival · 2026-10-01
Tank Math Lab: aquarium decisions by the numbers
Free freshwater aquarium calculators and guides help fishkeepers plan stocking, calculate fishless-cycle ammonia doses, and understand water chemistry.
- For
- Freshwater aquarium keepers planning stocking or fishless cycling
- Worth noticing
- Its worked 20-gallon example distinguishes 20 high from 20 long and considers net gallons, bioload, and fish behavior.
Field notes
The stocking planner says it estimates net water volume, bioload, and compatibility; the dosing tool covers household ammonia or ammonium chloride and converts units to a target ppm. Guides include a worked 20-gallon comparison, nitrate-change calculations that account for tap-water nitrate, and test-kit measurement caveats. The site states that calculator estimates should be verified with water tests and marks some measurement-dependent guidance as “Field test pending.”
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
One card from the complete issue