Testwater support

No. Readings are unlimited on both plans, free included.

Free: one tank, with unlimited readings, charts against your target ranges, maintenance tasks and reminders, CSV import and export, and backup and restore, for as long as you like.

Testwater Plus adds unlimited tanks, the reef dosing calculator, the planted fertiliser schedule and logging doses from them. It's £1.99 a month or £12.99 a year in the UK (elsewhere the App Store shows the price in your currency before you confirm), auto-renewing, with no free trial. The dosing calculator and the fertiliser schedule are part of Plus on every tank, your free one included. The full terms are in the Terms of Use.

Sign in with the same Apple Account, then in Testwater go to Settings and tap Restore Purchases. The subscription screen also has a Restore Subscription button.

In Testwater, go to Settings and tap Manage subscription. Or on your iPhone, go to Settings › [your name] › Subscriptions, then Testwater.

Cancel at least 24 hours before the end of the current period to stop the next renewal. Plus stays active until the end of the period you've paid for.

Subscriptions are sold by Apple, so refunds are Apple's to give. Ask at reportaproblem.apple.com. We can't issue refunds ourselves.

Nothing is deleted. Your oldest tank keeps working as on the free plan. Your other tanks become read-only: you can still view, export and delete them, and their reminders are paused. The reef dosing calculator and the fertiliser schedule lock on every tank, though your dose log stays readable. If you have more than one tank, Testwater tells you once, with a Plus has ended notice. Subscribe again and everything works as before, reminders included.

Plus isn't treated as ended until the App Store confirms it, so being offline when it renews doesn't end it.

Testwater doesn't sync through iCloud, so move it with a backup file:

1. On the old iPhone, go to Settings › Import and export and tap Export backup. Save or send the file (testwater-backup-date.json) somewhere the new iPhone can reach, such as Files.
2. On the new iPhone, open Testwater and tap Restore a backup on the welcome screen (or go to Settings › Import and export), then tap Restore backup, choose the file and tap Replace.
3. Set your units again in Settings: they aren't part of the backup.
4. If you have Plus, tap Restore Purchases in Settings: your subscription isn't in the backup file. If any tasks had reminders on, iOS asks whether Testwater may send notifications.

If you set up the new iPhone from a backup of the old one (iCloud Backup or a computer), Testwater's data comes across with it.

Yes, as a CSV file. Go to Settings › Import and export › Import CSV. Testwater reads comma, semicolon and tab-separated files saved with a .csv name (rename a .tsv or .txt export to .csv first), with one reading per row or one column per parameter. It understands day-first and month-first dates (and asks when a date could be read either way), decimal commas in semicolon and tab files, and values like < 0.02.

Before anything is imported it shows a preview: which tank the readings go into, how it matched the columns, how many readings it found and any rows it had to skip and why. Readings already in the tank are skipped as duplicates. Without Plus, imports go into your oldest tank.

Everything on the iPhone is saved first, so Settings › Import and export › Restore previous data can undo an import.

• Check the task has Remind me switched on: open Tasks for the tank and tap the task.
• Check notifications are allowed: Settings › Apps › Testwater › Notifications. If they're off, Tasks says "Reminders are off" with a button to fix it.
• Reminders are paused for read-only tanks: without Plus, only your oldest tank's reminders arrive.

For alkalinity, calcium and magnesium on a marine tank, you add your product once from its label: how many millilitres raise the level by how much in how many litres or gallons. You also set the most it may raise the level in a day: it starts at 1.0 dKH, 20 ppm of calcium or 100 ppm of magnesium, so change it to your product's own figure. Testwater takes the current value from your latest test, and warns you to test first if that's more than two days old. The target starts at the middle of your range.

It works out the total from your tank's volume, splits it over enough days to stay within the daily limit and shows the arithmetic under the result. It asks you to confirm an unusually large dose before logging it. Doses you log after the test count towards the rest of the plan.

Dosing is part of Plus, on marine tanks (reef dosing) and planted tanks (the fertiliser schedule), not freshwater or pond tanks.

The fertiliser schedule for planted tanks works out grams per dose of each dry salt from Estimative Index targets or your own weekly targets. In both cases, check with your test kit before and after dosing: the calculator is only as right as the figures it's given.

Yes. Go to Settings › Units to choose °C or °F, litres, UK gallons or US gallons, and dKH or meq/L for alkalinity. It only changes how numbers are shown; everything you've recorded stays as it is. An iPhone set to US measurements starts in °F and US gallons.

Delete single readings, tasks and doses where they appear in Testwater. Deleting a dosing product means opening it in the dosing calculator, which needs Plus. On a read-only tank you can't delete anything inside it, but you can delete the whole tank. To delete a parameter and its readings, open the tank, tap Show or add parameters, swipe the parameter and tap Delete. To delete a tank and everything recorded for it, open the tank, tap Edit, then Delete tank, and type the tank's name to confirm. Deleting the Testwater app deletes everything it stored on your iPhone. The Privacy Policy has the detail.

Nothing has been deleted. Make some space if the iPhone is full, restart it, then open Testwater again. If it keeps happening, write to us with the form above, with your iPhone model and iOS version, and we'll help.

Testwater says what happened:

• Purchases are turned off. This iPhone doesn't allow purchases (Settings › Screen Time). Nothing was charged.
• Couldn't reach the App Store. Check your connection and try again. Nothing was charged.
• Couldn't subscribe. Nothing was charged; try again in a moment.
• Waiting for approval. With Ask to Buy, Plus turns on when the purchase is approved. Nothing has been charged yet.
• Couldn't confirm the purchase. Tap Restore Subscription on the same screen. If Plus still doesn't turn on, write to us with the form above.

Without Plus, only your oldest tank can be changed; the others can be viewed, exported and deleted. You'll see this after Plus ends, or after restoring a backup with several tanks on the free plan. Subscribe, or restore your subscription in Settings, and they work as before.