Support

Anything not answered here — email hello@onefishtwofish.app and you will get a reply from a person.

Getting in touch

One address for everything — bugs, questions, feature requests, disagreements about a threshold: hello@onefishtwofish.app.

If you are reporting something broken, these four lines get it fixed much faster:

• Which iPhone or iPad, and which version of iOS or iPadOS.
• The app version, from the bottom of the Settings screen.
• What you did, what you expected, and what happened instead.
• A screenshot, if the problem is something you can see.

Please do not send anything sensitive. Nothing in a fish tank log needs to be, and the app never asks you for personal information in the first place.

Readings and grading

Why is my ammonia flagged when the test says it is low?

A liquid test kit reads total ammonia — the harmless NH₄⁺ plus the toxic NH₃. The split between them depends heavily on pH and temperature, so the app calculates the free NH₃ fraction using the pH and temperature from the same test and grades on that instead of the raw number.

In a warm, alkaline tank the same 0.25 ppm reading is roughly sixty times more toxic ammonia than in a cool, acidic one. That is why two tanks with an identical reading get different verdicts.

Why does it say nitrate is fine when it is above my target?

If you have recorded a tap water baseline and your supply already carries nitrate, the achievable ceiling moves up to your tap value plus a small margin. Chasing a target below what comes out of the tap is not possible with water changes, so the app stops flagging it and tells you the real levers instead — feeding less, or more plants.

Why is nothing showing on the charts?

Sparklines need history. One test gives a tile with a value; trend detection needs at least three tests spread over five days or more before it will say anything about direction, so it does not shout about noise.

I disagree with a threshold.

Change it. The profile you pick when creating a tank only seeds the starting values — temperature target, pH range and nitrate ceiling are all editable per tank in Settings, and grading follows your numbers from then on.

Volume

The volume it gives is lower than the tank's advertised size.

That is the point. A tank sold as 180 litres is the outside of the box. The app works from your measurements and can subtract the thickness of the glass and the gap between the waterline and the rim, which gets you the number that actually matters for dosing and water changes. Substrate and hardscape displace more on top of that.

Which measurements do I need?

It depends on the shape — a rectangle needs length, front-to-back and height; a cylinder needs diameter and height; a bowfront also needs the depth of the bow. Every measurement is in centimetres and every result is in litres.

Reminders

I am not getting reminders.

• Check reminders are switched on for that tank in its Settings.
• Check iOS Settings → Notifications → One Fish Two Fish, and that Allow Notifications is on.
• Check Focus or Do Not Disturb is not suppressing them.
• Log at least one water change — the schedule is worked out from your history, so with nothing logged there is nothing to pace against.

Why does the interval keep changing?

Because it is measured, not fixed. The app looks at the gaps between the water changes you have logged and reminds you on that rhythm. Change water more often for a while and the reminders tighten up to match.

Your data

Can I get my history onto a new phone?

Restoring a new device from an iCloud or computer backup of the old one brings the app's data with it, like any other app. There is no account to sign into, so a fresh install on a new phone with no restore starts empty.

Can I get my data out?

Not in the first release. Export is on the list — if it matters to you, say so in an email; that is genuinely how the order gets decided.

How do I delete everything?

Delete individual tanks in the app, or delete the app to remove all of it at once. There is no server copy — see the privacy policy.

Scope

Marine, brackish or pond?

Freshwater only. The ammonia chemistry the grading depends on behaves differently in salt water, and reef keeping needs a whole set of parameters the app does not track. Building a bad version of both was not worth it.

Is this veterinary advice?

No. The thresholds come from published freshwater aquaculture figures and the advice is the conventional response to a given reading, but a struggling tank can have causes no water test reveals. For a sick or dying animal, an aquatic vet beats an app.