We have kept this genuinely short because there is genuinely not much to say. AquaCalc uses no advertising cookies, no tracking cookies and no third-party profiling.
Last updated: 17 June 2026 · Applies to: aquacalc.io and all subdomains
Short version: We use no cookies for advertising or tracking. We use PHP session cookies only to protect the feedback form from abuse, and browser localStorage (which is not a cookie) for saving your tank profiles. Plausible Analytics operates without cookies entirely.
A cookie is a small text file stored on your device by a website. Cookies can be used for many purposes — from keeping you logged in, to tracking your behaviour across multiple websites for advertising purposes.
UK law (the Privacy and Electronic Communications Regulations — PECR — and UK GDPR) requires websites to tell you what cookies they use and, where required, to ask for your consent before setting them.
When you visit the feedback form, our server creates a temporary PHP session to:
This cookie:
| Property | Value |
|---|---|
| Name | PHPSESSID |
| Purpose | Security (CSRF protection & rate limiting) |
| Duration | Session only — deleted when you close your browser |
| Third party? | No — set by our server only |
| Tracks you? | No — contains only a random session identifier |
| Consent required? | No — strictly necessary for security |
Under PECR, strictly necessary cookies do not require consent. This cookie is not used to identify you, track your behaviour or store any personal data beyond the session duration.
| Type | Used? | Notes |
|---|---|---|
| Advertising cookies | ✕ No | We run no advertising of any kind |
| Tracking / analytics cookies | ✕ No | Plausible Analytics is cookieless — see below |
| Social media cookies | ✕ No | No social sharing buttons or embeds |
| Profiling cookies | ✕ No | We build no user profiles |
| Cross-site tracking | ✕ No | We do not track you across other websites |
| Persistent login cookies | ✕ No | AquaCalc has no accounts or login system |
AquaCalc uses your browser's localStorage to save your tank profiles, settings and preferences. localStorage is not a cookie — it is stored only on your device, is never transmitted to our servers, and cannot be read by any other website.
You can clear your AquaCalc localStorage at any time by clearing your browser's site data, which will reset all your profiles.
We use Plausible Analytics to understand how many people visit AquaCalc and which pages are most popular. Unlike most analytics tools, Plausible sets no cookies whatsoever. It operates using a daily hash of your IP address and user agent to count unique visitors — a hash that cannot be used to identify you and is discarded after 24 hours.
Plausible is fully compliant with UK GDPR, EU GDPR and PECR. No consent banner is required for Plausible because it collects no personal data and sets no cookies. You can verify this at plausible.io/data-policy.
The dashboard loads the Chart.js library from Cloudflare's CDN (cdnjs.cloudflare.com). This is a standard CDN request and does not set any cookies, though Cloudflare may log your IP address as part of normal CDN operation. See Cloudflare's privacy policy for details.
You can control and delete cookies through your browser settings. Deleting the PHP session cookie will not affect your use of the dashboard — it is only set on the feedback form page. Instructions for managing cookies:
If we ever introduce new cookies or change how we use existing ones, we will update this page and revise the date at the top. Given the privacy-first design of AquaCalc, we do not anticipate significant changes.
For any questions about our use of cookies, please use the feedback form. You also have the right to complain to the Information Commissioner's Office (ICO) at ico.org.uk if you believe we are handling cookies unlawfully.