Privacy policy
Last updated 25 July 2026
Aquafern is made by StarlingPetals. This policy covers the Aquafern iOS app and the aquafern.app website. It is short because the app genuinely does very little with your data.
The short version
Aquafern has no servers. There is no account to create, nothing to log in to, and no database of ours that your tank readings are ever written to. We cannot see your data, and we have not built anywhere to see it from.
What stays on your device
Everything you enter in the app:
- Tank names, types, volumes and start dates
- Water parameter readings and the notes attached to them
- Maintenance events such as water changes and filter cleans
- Dosing records
- App preferences such as units and reminder times
This is stored in the app's own storage on your device, and — if you are signed in to iCloud with iCloud Drive turned on — mirrored to the private database of your own iCloud account so it survives losing your phone and appears on your other devices.
That iCloud copy is governed by Apple's privacy policy and is subject to your Apple Account's own protections. StarlingPetals has no access to it. Turning iCloud off in iOS Settings stops the sync; your data remains on the device.
What we collect
Nothing. Aquafern contains no analytics SDK, no crash reporter, no advertising identifier, no tracking pixels, and no third-party marketing tools. We do not ask for your email address. We do not know how many tanks you keep or what is in them.
Subscriptions
If you buy Aquafern Pro, the purchase is processed by Apple through the App Store. We never see your payment details. Apple provides us with anonymous aggregate sales reporting.
We use RevenueCat, Inc. to validate subscription receipts and tell the app whether Pro is active. To do that, RevenueCat receives an anonymous identifier it generates for your installation, your App Store transaction and receipt information, and basic device and app metadata such as device model, operating system version and app version. It does not receive your name, your email address, or any of your tank data. RevenueCat acts as our data processor; see revenuecat.com/privacy.
Notifications
Water change and test reminders are scheduled locally by your device. They are not push notifications, no server is involved, and nothing about your schedule leaves your phone.
Exports
CSV and PDF exports are generated on your device and go only where you send them. Nothing is uploaded as part of creating them.
This website
aquafern.app is a set of static files hosted on Cloudflare Pages. It sets no cookies and has no advertising or cross-site tracking.
It does use Cloudflare Web Analytics so we can see roughly how many people visit and which pages they read. It is cookieless and does not fingerprint you or follow you to other sites: it records page views, referring site, approximate country, browser and operating system, and page-load speed. It cannot identify you, and it is not linked to anything in the app. See Cloudflare Web Analytics.
Cloudflare also processes standard server request logs (including IP addresses) to serve and protect the site; see cloudflare.com/privacypolicy.
None of this applies to the app. Aquafern itself contains no analytics of any kind — the website and the app are entirely separate.
Children
Aquafern is not directed at children under 13 and collects no personal information from anyone, including children.
Your rights
Because we hold no personal data about you, there is nothing for us to export, correct or delete on request. Your own copy is entirely under your control: delete a tank in the app to remove it and everything attached to it, use Export to take a full copy with you, and delete the app (and remove its data in iOS Settings → iCloud) to remove it completely.
Changes
If this policy changes we will update the date at the top of this page. Material changes will be noted in the app's release notes.
Contact
Questions about privacy: privacy@aquafern.app.