Contact
For anything to do with this site — a correction, a question about a guide, a bug in one of the tools, or a suggestion for something worth building — the address is:
What is worth writing about
Corrections. These are the most useful messages to receive. If a guide states something incorrectly, or a calculator produces a result you can show is wrong, please say which page and what the correct figure or behaviour should be. Fixes are made promptly and the page is updated.
Bugs. If a tool misbehaves, it helps enormously to know which browser you were using and what you entered. Several of the tools do their work inside your browser rather than on a server, so behaviour occasionally differs between browsers in ways that are hard to reproduce blind.
Suggestions. If there is a calculation you keep doing by hand, it may be worth building. No promises, but the list of tools here grew from exactly that kind of suggestion.
What this site cannot help with
It cannot give individual professional advice. The guides explain general principles, and questions like whether a specific recipe is safe, whether a particular kiln schedule suits your clay, or whether a given fish belongs in your tank depend on specifics only you can see. Where something carries real risk — caustic chemicals, high temperatures, live animals — please rely on the manufacturer's data sheet, a local expert, or the relevant regulations rather than a general reference site.
Response time
This is a personal project run alongside other work, so replies are not instant. Corrections and bug reports are prioritised over everything else.