Privacy Policy
We respect that your reef setup is personal. Here's exactly what we do with the data you give us, in plain language. TankSensei is operated by Printed Reef Inc.
1. What we collect
When you create an account:
- Email address (for sign-in, tank and maintenance notifications, and product news: new features and updates from the TankSensei team, with an unsubscribe link in every one and a switch under Account, Notifications)
- Password if you use one — hashed with bcrypt; we never see the plaintext
When you use the app:
- Tank details (name, volume, livestock, equipment, photos you upload)
- Test readings (alk, Ca, Mg, nitrate, phosphate, salinity, etc.)
- ICP lab reports you upload — the PDF itself is kept in your account so you can open it again, along with the values we read from it. Delete a test and its PDF goes with it.
- Tasks, supplies, dose events you log
- Sessions (which device you're signed in on)
- Mobile phone number — only if you opt in to SMS alerts (Account → Notifications). We store the number and a timestamp of your consent.
- Push notification subscriptions — if you turn on notifications, your browser gives us a subscription address to deliver them to
- Location — only if you use Near You. The location you share (your device's GPS, or a ZIP code or city you type) is used to find nearby stores, clubs and events, and is remembered on your own device so you don't have to enter it again. Places, events and photos you add to Near You are shared with other users. A store's or club's own email, whether given with a listing or published on its own website, is kept private: it is never shown, and is used once, to tell the store or club that it is listed and give it a private link to check the listing, post its events or ask to be removed. What a store sends through that link comes to us to check before it shows.
- Anything you choose to send us: feedback, emails you send to us (kept in our inbox so we can read and answer them; if the address has no TankSensei account, the conversation is deleted 90 days after its last message, and its backup copies roll off within about 8 weeks after that; an email that became a feedback ticket is kept with that ticket; an order you forward to our restock address keeps only its sender and subject there), ICP report text you submit for a lab we don't support yet, and photos you submit to the shared livestock catalogue
- Your email and controller type if you join a waitlist (for example, for Printed Reef displays). We use it only to tell you about that list.
If you use a Printed Reef display or connect a controller:
- Device data — the display's identifier (derived from its network hardware address), device type, firmware version, when it was last online, and the readings it sends
- CoralVue HYDROS — if you connect HYDROS, we store encrypted either the key you made in the HYDROS app (you can delete it there at any time) or, on the older link, your HYDROS sign-in, and receive your controllers' readings and settings from HYDROS
- Neptune Apex readings a display polls on your local network and forwards to us
Automatically, when you use the Service:
- Server logs — IP address, browser type and the pages or API calls requested, kept for security and troubleshooting and deleted on a rolling basis by our hosting provider
- When a new account is created, its email, IP address and browser type are sent to our team by email so we can spot abuse
- How you use the app: which screens and features you use and when you were last active, tied to your account, so we can fix problems and decide what to build.
- If you type your email to sign in or sign up but don't finish, that address, the step you reached and when. We keep it for up to 90 days so we can see where signing up gets stuck, and we don't email you because of it.
- Crash reports, tied to your account.
When you visit our website pages:
- Page views, the browser and device type your browser reports (its user agent), referrer, and the short source code in the address if you came through a tagged link (for example a QR code at a reef show)
- A random visitor id (see Cookies), so we can count repeat visits. If you sign in from the same browser, your visits to these pages are linked to your account.
- Your IP is hashed with a per-server salt before storage — we never store raw IPs from anonymous visitors
2. Why we collect it
To make the app work. Test readings drive the Sensei Score. Livestock data drives the species fit checker. Photos let you see your tank's progression over time. The hashed visit data tells us whether the landing page is reaching people.
3. What we share with third parties
We don't sell your data or share it for advertising. We use these service providers to run TankSensei, and each receives only what it needs for its job:
- Railway — hosts the app and its database, so it stores all the data described above on our behalf.
- Backup storage — an S3-compatible cloud storage provider holds our database and file backups.
- Anthropic (Claude AI) — when Sensei writes your tank summary, livestock advice or dose commentary, answers a question you ask about your tank, reads a photo you upload (a test result, a coral to identify, a tank photo to compare, or a product label), looks up a product you type in, reads an order-confirmation email you forward to us, or reads the public website of a store or club you recommend in Near You, the relevant tank data and that photo or text are sent to their API with a hashed version of your user id (not your email). A forwarded email is sent as you forwarded it, so it can include what the retailer put in it, such as your name or address. When we answer feedback or an email you send us, we may ask it to help draft the reply: your message, the earlier replies in that conversation, and a short summary of your account (your tanks' names, types and sizes, how many devices you have linked, whether HYDROS is connected and notes on your notification settings) are sent, with the first line of other open messages so it can spot ones asking the same thing, never an email address. We read and edit every reply before it goes out. We may also have Claude look into feedback you send, to find and fix what went wrong: your message and its subject, its screenshots, the earlier replies, the app screen, browser, screen size and theme you sent it from, our own notes on it, and, if you sent it while signed in, a short summary of your tanks (their names, types, sizes, units, stage, which tests they show and whether each has a range, and whether a device or HYDROS is linked) are sent, never an email address. It never writes to you itself, and when it fixes something it describes the problem in our private code repository without your name or address. When you email us, the subject and your words (never your address) are sent to it once, to sort whether the email is feedback about TankSensei. See Anthropic's privacy policy.
- Resend — used to send magic-link sign-in emails, notification emails, product news and the one email a listed store or club gets. They see the address it goes to.
- Telnyx — used to deliver SMS text alerts to the mobile number you opt in with. They process your number solely to send those messages.
- Amazon Web Services (AWS IoT) — carries the connection between Printed Reef displays and TankSensei: readings from the display, and your tank data sent back to it.
- CoralVue HYDROS — only if you connect it. We fetch your controllers' data from HYDROS with the key you made in the HYDROS app, or, on the older link, the sign-in you gave us. We only read; we never change a setting on your controller.
- Push notification services — push alerts are delivered through your browser's or phone's push service (for example Apple, Google or Mozilla), which receives the notification to pass on to your device.
- OpenStreetMap — when you type an address or ZIP code in Near You, or the name of a store or club you recommend, our server looks it up with OpenStreetMap's geocoder, with the area you are browsing but never your account.
We may also disclose information if the law requires it, to protect people's safety or our rights, or to a buyer if Printed Reef Inc. is sold or merged, in which case this policy continues to apply to your data.
SMS / text message alerts
Text alerts aren't switched on yet. This section applies once they are.
If you opt in (Account → Notifications → Text message), TankSensei sends you critical, time-sensitive tank alerts by SMS — e.g. a chemistry parameter out of safe range or a monitoring device offline. These are transactional notifications only; we never send marketing texts. Message frequency varies with your tank's activity. Message and data rates may apply.
You consent by entering your number and tapping Confirm. You can opt out any time by replying STOP to a message, or by turning SMS off in Notifications; reply HELP for help. Consent is not required to use TankSensei and is not a condition of any purchase.
No mobile information — your phone number or your SMS opt-in/consent — is ever shared with third parties or affiliates for marketing or promotional purposes. The only third party that receives your number is our messaging carrier (Telnyx), solely to deliver the alerts you asked for.
We do not use:
- Not usedGoogle Analytics, Mixpanel, Hotjar, or any third-party analytics
- Not usedFacebook/Twitter/etc. tracking pixels
- Not usedCross-site fingerprinting
- Not usedAd networks
You can verify this yourself: open browser devtools on tanksensei.com and watch the network
tab. Apart from our own domain, your browser loads fonts from Google Fonts
(fonts.googleapis.com), species photos in the livestock catalogue from
Wikimedia and iNaturalist, and map tiles on the Near You page from OpenStreetMap. Like any
website, those services see your IP address when your browser requests from them; none of
them is used for tracking or advertising.
4. Cookies
- A session cookie for signed-in users (HttpOnly, Secure, SameSite=Lax)
- A separate admin cookie for site admin login (HttpOnly, Secure, SameSite=Lax)
- A referral cookie, only if you arrive through a friend's invite link, so we can credit the invite when you sign up. It holds the invite code and expires after 30 days.
- A source cookie, only if you arrive through a tagged link (for example from a QR code at a reef show), so we know which events and links bring people in. It holds a short code and expires after 30 days. If you create an account, the code is saved with it so we can see how people from each source use the app.
- A visitor cookie, set when you open our website pages. It holds a random id, so we can count repeat visits and, once you sign in on that browser, see those visits with your account. It expires after a year.
- A short-lived cookie that remembers where you were going (a display pairing link or a tank invite) while you sign in. It expires after an hour.
The app also keeps your preferences (theme, Home layout, saved Near You location) in your browser's local storage. That stays on your device.
If you're in the EU, the EEA or the UK, we ask first: the visitor, source and referral cookies are set only after you choose Accept, and your answer is kept in a cookie for six months. You can change it any time from Cookie settings at the foot of each page. Choosing No thanks deletes any of those three cookies you already have.
No third-party cookies. No tracking pixels. No browser fingerprinting.
5. AI spend tracking
Every AI call is recorded in our internal
ai_usage table with your user id, the feature it was for, token counts, and
cost. This drives per-user spending caps so a compromised account can't burn unbounded AI
cost. The usage log keeps only this metadata, not the contents. The answers themselves, like your
tank summary, are kept as part of your tank data.
The questions you type into "Ask the tank" are also kept, with your account, for 90 days and then deleted, so we can see what keepers need and improve the app. When we look for patterns in them, only the question text is used, never your name, email or tank records. Your photos and the answers are not part of this.
6. Your rights
You can:
- Export any tank any time from its settings, as an Excel file with every reading, dose and water change, its parameters, livestock, equipment, supplies, tasks, journal, ICP results and quarantine logs
- Delete your account any time from Account in the app (unlink any Printed Reef display first) — data goes within 30 days. Copies in our backups roll off as those backups expire, within about 8 weeks. Content you shared publicly may stay where removing it would break a shared listing.
- Ask what we have on you — email [email protected]
- Correct anything that's wrong — most things you can edit yourself; for anything else, email us
These apply regardless of where you live. We do this not because GDPR/CCPA says so, but because it's the right way to run a tool that touches your hobby.
7. Security
- Passwords are hashed with bcrypt cost 10
- Sessions use HttpOnly Secure SameSite=Lax cookies
- Sign-in links are single-use and expire quickly (15 minutes by default)
- All connections are TLS
- AI API calls are guarded by per-user spend caps + a global monthly cap + a kill switch
We're a small team. If we have a security incident affecting your data, we'll tell you within 72 hours of discovering it.
8. Age
You must be 18 or older to use TankSensei. We don't knowingly collect data from anyone under 18, and we delete it if we learn we have.
9. Changes to this policy
If we change it in a material way, we'll prompt you to re-acknowledge on your next sign-in. The version date at the top shows when it last changed.
10. Contact
Email [email protected] for any privacy question.