Contact

Questions, corrections, and tool suggestions are all welcome — corrections most of all. If a formula, assumption or explanation on any page looks wrong to you, please say so and we will investigate and fix it.

To help us respond usefully, include:

• the page or calculator you are writing about,
• the inputs you used and the result you got,
• what you expected instead (and, for corrections, a source if you have one).

We are a small operation and answer in the order messages arrive — usually within a few days.

A note on advice

We can explain what our calculators do and why, but we cannot diagnose sick fish or approve structural plans by email. For animal-health questions please consult an experienced aquatic specialist or aquatic veterinarian; for floors, stands and large-tank installations, a structural engineer or qualified builder.