- Your tank stays on your device. Dimensions, water type, volumes and test readings are saved in your browser's local storage. They are never transmitted to us.
- There are no accounts. Nothing to sign up for, no password, no profile on our side.
- We don't sell or share personal data. Ever, to anyone.
- Affiliate links set cookies — on the retailer's side, not ours — when you click through to a shop.
Who's responsible for this site
AquariumToolbox (aquariumtoolbox.com) is run by Brian Hamilton. For data-protection purposes, that's the data controller. Privacy questions and requests go to [email protected], and we answer all of them.
Your tank profile stays in your browser
The calculators remember your tank so you don't retype it every visit, and the dashboard remembers your last test so it can tell you what changed. All of it is written to local storage in your own browser. It is not sent to our servers, we cannot see it, and it doesn't exist anywhere except on the device you typed it into.
Precisely, this site writes three entries, each named with the prefix
atb:
atb:tanks— your tanks: an optional name, unit preference, water type, shape and dimensions, glass thickness and fill line, volume, sump, substrate depth, rock displacement, the nitrate in your tap water, and the strengths of the two-part products you told the reef tools about.atb:activeTank— which of those tanks you're currently working on.atb:lastTest— the most recent readings you chose to save, and when: alkalinity, calcium, magnesium and salinity on a reef; ammonia, nitrite, nitrate and pH on a freshwater tank.
That's the entire list, and you can verify it: open your browser's developer tools, look at local storage for this domain, and what you see is what there is. It also means the data isn't backed up or synced — clearing your browser data clears your tank, and a different device starts fresh. You can wipe it yourself right now:
Clear the data this site has stored on your device
Removes your saved tanks and last test readings from this browser.
Your numbers in the address bar
Every calculator writes what you type into the page's own web address, so a result stays put if you reload and can be shared or bookmarked — that's what the "copy link" button hands you. Two honest consequences. A link you share contains those numbers, so treat it the way you'd treat any note about your tank. And if someone opens a link like that, the address including its values appears in our host's ordinary server logs, the same way any page request does. Typing into the calculator doesn't send anything anywhere; only opening a link does.
What our host records
The site is served by our hosting provider, which keeps standard server logs — IP address, browser type, the page requested, and the time. These are generated automatically by essentially every website on the internet, are used for security and diagnosing faults, and are held on our host's normal retention schedule. We don't combine them with anything else or use them to build a picture of you.
Analytics
We currently run no analytics at all — no Google Analytics, no tracking pixels, no third-party scripts watching what you do here. If that changes we'll say so on this page, name the provider, and ask for consent first where the law requires it.
Affiliate links
Some links to products are affiliate links: if you buy something after clicking one, we may earn a commission at no extra cost to you. Clicking an affiliate link takes you to the retailer's own site, where that retailer typically sets a cookie to attribute the sale. That cookie is theirs, governed by their privacy policy, and it's how they know the visit came from us. We never see your order details, your payment information, or what you bought — only, at most, an anonymous count of sales attributed to the site.
Our affiliate disclosure explains which programs we're part of and how it affects what we recommend (short answer: it doesn't — the math is the math).
Emailing us
There's no contact form here and no mailing list — just email addresses. If you email us, we keep the message so we can reply and, where it's a correction or a bug, so we can fix the thing you reported. We don't add you to anything, because there's nothing to add you to.
Cookies, honestly
AquariumToolbox sets no cookies of its own. Your tank profile uses local storage, which is a different mechanism: it's readable only by this site, it isn't attached to network requests, and it isn't used to track you. The only cookies you might ever pick up here are a retailer's own, after clicking through to their shop — and as above, there are no such links on the site yet.
Your rights
Under the UK/EU GDPR you have the right to access, correct, delete, or restrict the processing of personal data we hold about you, to object to processing, and to complain to a supervisory authority. Under the CCPA/CPRA, California residents have rights to know, delete, and opt out of the sale or sharing of personal information — we don't sell or share it, so there's nothing to opt out of.
In practice, the personal data we hold amounts to emails you've chosen to send us. Write to [email protected] and we'll act on any of these requests. Your tank profile isn't included in that, for the simple reason that we've never had a copy — use the button above and it's gone.
Children
This site is aimed at adults keeping aquariums. It isn't directed at children, and we don't knowingly collect information from anyone under 13.
Changes to this policy
If we add anything that changes the picture — analytics, an email list, a new third-party service — we'll update this page and change the date at the top. Because there are no accounts, we can't email you about it, so the date is the honest signal to watch.
Contact
Privacy questions: [email protected]. Corrections to the math: [email protected]. Anything else: the contact page.