Terms of use
Last updated 25 July 2026
These terms cover your use of the Aquafern app for iOS, published by StarlingPetals ("we", "us"). Installing or using Aquafern means you accept them.
The licence
We grant you a personal, non-transferable, non-exclusive licence to use Aquafern on Apple devices you own or control, as permitted by the App Store Terms of Service. You may not resell it, rent it, reverse-engineer it, or strip out its identification or proprietary notices.
Aquafern Pro
Aquafern is free to use with one tank and thirty days of charted history. Aquafern Pro is an auto-renewing subscription that unlocks unlimited tanks, your full history, reminders, export, the dosing log and custom target ranges.
- Price and period. $29.99 per year or $4.99 per month, in US dollars. Local prices are set by Apple's pricing tiers and shown in the app before you buy.
- Free trial. The annual plan includes a 3-day free trial for new subscribers. If you cancel before the trial ends you are not charged. Any unused portion of a trial is forfeited if you buy a subscription during it.
- Billing. Payment is charged to your Apple Account at confirmation of purchase.
- Renewal. The subscription renews automatically unless you turn off auto-renew at least 24 hours before the end of the current period. Your account is charged for renewal within 24 hours before the period ends.
- Managing it. Manage your subscription and turn off auto-renew in your Apple Account settings after purchase. We cannot cancel it for you.
- Refunds. Purchases go through Apple, so refunds are handled by Apple under their policy at support.apple.com/billing.
If your subscription lapses, none of your data is deleted. Tanks and readings beyond the free limits become hidden in the app, remain backed up, and reappear if you subscribe again.
Your data
Your tank log is yours. It is stored on your device and, if iCloud is enabled, in your own iCloud account — not on any server of ours. You are responsible for keeping your Apple Account secure and for keeping your own copies of anything you cannot afford to lose; the app's CSV and PDF export exists for exactly that. See the privacy policy for detail.
Aquafern is not veterinary advice
Target ranges in Aquafern are general hobby guidance drawn from mainstream aquarium references. They are defaults, not prescriptions: species, setups and local water vary enormously, which is why every range is yours to change. Aquafern does not diagnose anything and is not a substitute for your own judgement or a qualified aquatic vet. Decisions about livestock are yours.
No warranty
Aquafern is provided "as is", without warranty of any kind to the fullest extent the law allows. We do not warrant that it will be uninterrupted or error-free.
Limitation of liability
To the extent permitted by law, StarlingPetals is not liable for indirect, incidental or consequential damages, or for loss of data, arising from your use of Aquafern. Our total liability is limited to the amount you paid us for the app in the twelve months before the claim. Nothing here limits liability that cannot lawfully be limited.
Changes
We may update these terms; the date at the top will change and material updates will appear in the app's release notes. Continuing to use Aquafern after a change means you accept it.
Apple
Apple is not a party to these terms and has no obligation to provide support for Aquafern. Apple and its subsidiaries are third-party beneficiaries of these terms and may enforce them against you.
Governing law
These terms are governed by the laws of [your jurisdiction], without regard to conflict-of-law rules.