What a water reminder app actually has to do
Two things, and they pull against each other. It has to interrupt you often enough that you notice you have not drunk anything since breakfast, and it has to cost so little attention that you never turn it off. Almost every app in this category fails the second half: it nags on a fixed schedule, it fires during meetings, and logging a glass takes four taps in a window you have to go and find.
Aqumi is the one this article walks through. It lives as a droplet in the macOS menu bar, keeps its log on the machine, and everything below is in the shipping version.
The droplet in the menu bar
The status item is the whole interface most days - that and the desktop widget further down. It is the Aqumi drop on a small navy disc, with a ring around it that fills as you get closer to the day's goal and turns green once you reach it. Out of the box that is all there is: no number competing with the clock, and a ring that is either nearly empty at four in the afternoon, which tells you something, or it is not.
If you would rather read a number, Settings -> General -> Menu bar puts one next to the drop: today's amount ("1.2 L") or the percent of your goal. Drop only stays the default.
Clicking it opens the popover. Pressing Command Shift W opens the same popover from anywhere on the Mac, and Command Shift L logs your first Quick Add drink without opening anything at all. Both use Carbon hotkey registration, so Aqumi needs no Accessibility permission to make them work.
Logging, in one tap or one keystroke
Logging is the part that has to be nearly free, so the popover leads with it: a row of drinks, each button showing its volume with the drink's name under it, one tap away.
The drinks are yours to shape. Aqumi seeds a few on first launch, and you add, edit, reorder and pin your own in Settings -> My Drinks - a 250 ml glass, the 750 ml bottle on your desk, the coffee you were going to count anyway. Whichever ones you pin show up in the popover's quick-add row, and the first of them is the one Command Shift L and a reminder's Log button reach for. For anything else, Custom takes any amount and lets you pick which drink it was, so its hydration factor still counts.
Each drink carries a hydration factor alongside its volume, which is the detail that makes counting anything other than water honest. Water is 1.0, milk counts for 1.2, a sports drink 1.1, an energy drink 0.9 and a beer 0.75 - so a 500 ml beer moves the ring by 375 ml, and the app does not pretend otherwise. The defaults come from the Beverage Hydration Index, which is also why tea and coffee sit at 1.0 rather than below it: in that study they were not measurably worse than water. None of it is fixed - pick a drink type and the factor fills itself in, then move it anywhere between 0.5 and 1.5 in 5% steps. You can keep up to eight drinks, anywhere from 50 to 2000 ml each, and pin as many of them as you want to the quick-add row. Nothing stops you pinning all eight; the row just stops being a row at that point, which is the argument for two or three.
Coffee, tea and energy drinks also carry caffeine. They start from a typical amount per serving, which you change in the same editor - set it to 0 and the drink is a decaf. Once today has any caffeine in it, the popover shows the total next to today's list, and Settings -> My Drinks holds a daily limit, 400 mg unless you change it. Past it the total turns amber and one note goes out for that day, not one per cup. If you do not want any of it, the same page switches caffeine off.
Units are metric or imperial, and the choice is a display concern rather than a data one, so switching does not rewrite your history.
The widget on the desktop
The menu bar is not the only place Aqumi shows up. There is a desktop widget in two sizes, and it is there for the same reason the droplet is: the day you forget to drink is the day you never open the app.
The small card is the reading and nothing else - today's total against the goal, how far along you are, and one quick-add button. The medium one adds the week behind you: seven columns with the days you hit the goal in green, the current streak under them, and three quick-add buttons instead of one.
Pressing one logs that drink where you are standing. The app does not have to be running for the press to land - the drink waits in the container the two share and the app takes it up the next time it runs, while the widget counts it straight away rather than looking like nothing happened.
One difference worth knowing: a widget follows the system language rather than the one you picked inside Aqumi, the way every other widget on the desktop does.
Where the daily goal comes from
You fill in a short profile once - weight, age, sex and activity level - and Aqumi turns it into a daily volume. If you already know your number, type it in and the profile stops mattering.
That escape hatch is deliberate. The precise figure is the least important part of hydration tracking: the gap between a calculated 2.4 liters and the 2 liters you would have guessed changes nothing about your day, whereas noticing at 4pm that you have logged one glass changes it a lot. The goal exists to give the ring a top end, not to be medical advice.
Day starts at decides when the counter resets, anywhere from 03:00 to 06:00. It is a small setting with one specific reader in mind: if you are still working at two in the morning, a log that rolled over at midnight has already split your night into two half-empty days.
Reminders you can live with
Reminders run on an interval you set - 90 minutes out of the box - in one of two modes:
- Notification, the recommended one, posts a banner with a quick-log action on it.
- Silent posts nothing at all and lets the menu bar droplet be the reminder, which is where people who dislike reminders end up.
Notification is recommended for a reason worth naming: a droplet only works as a reminder if you look at it, and the day this app exists for is the day you do not. Silent is there so the app survives the week you cannot stand being interrupted, instead of being uninstalled during it.
The banner carries its own actions, so responding to it never means opening the app. Log records your first Quick Add drink and names it on the button - "Log Mug (350 ml)" - or a plain glass if nothing is pinned. Snooze 30 min and Snooze 1 hour push the next one back. Mute for today stops them until tomorrow, which is the button that keeps the app installed - an app you cannot silence for an afternoon is an app you uninstall on the afternoon you needed to.
Quiet hours cover the night. They default to 23:00 through 08:00 and take a range of your own, so nothing arrives while you are asleep. These are also ordinary macOS notifications, so a Focus or Do Not Disturb schedule holds them back the way it holds back everything else.
The day has its own interruptions, and Aqumi waits those out by itself. Under Hold reminders, During calls and presentations is on by default: while Zoom, Teams, Webex, FaceTime or Google Meet is the app in front, while Keynote or PowerPoint is showing a slideshow, or while your screen is mirrored to a projector, a reminder that comes due waits, and arrives a couple of minutes after the call or the slides end. When an app is full screen is the optional second switch, for movies, games and focused writing. A hold never lasts more than two hours, so a chat app left in front all day cannot switch reminders off by accident. None of this asks for a permission: Aqumi looks at which app is in front and whether a display is mirrored, never at the microphone or the camera.
Fixing a day
Logs go wrong. You tap the bottle when it was the glass, or you drink a liter at lunch and forget to log any of it. Any entry, today's or an earlier day's, opens when you tap it: change the amount, the time or the drink, or delete it.
Earlier days open from Statistics - tap a bar on the Week chart or a day on the Month calendar. A past day also has Add a drink, for the bottle you forgot, with a time of your choosing. The day's total, whether it hit its goal and the streak all follow the edit, so a day you actually made does not stay broken in the record because you were busy.
What a month of it looks like
The statistics screen answers the only question worth asking after a few weeks: is this actually working. It has four tabs - Today, Week, Month and Year.
Week is a bar chart with the daily average, the goal-hit rate and the streak. Month is a calendar: each day shaded by how close it came to the goal, the daily average above it and how many goal days the month has had, and you page back through every month you have logged. Year puts twelve monthly bars side by side with the year's total, the goal days, the best month and the drink you logged most.
All of it is computed from a log stored on your Mac. Nothing is written to Apple Health, nothing is uploaded, and there is no account to create before the first glass.
That last point is not a privacy flourish so much as a friction one. A hydration app that opens with a sign-up form is asking for more commitment than the problem deserves.
What it deliberately does not do
There is no phone app and no sync. Your log lives on one Mac, which is a real limitation and worth saying plainly: if you drink two liters away from your desk, Aqumi will not know until you add it.
There is no coaching layer - no scores, no badges, no daily summary email, no gamification beyond the streak. The interesting number is whether the ring is full, and everything else would be padding around it.
It asks for one system permission, notifications, and works without it in silent mode. No HealthKit, no location, no file access. The app is sandboxed, signed and notarised, and the only network traffic goes to our own servers - license checks, updates, config, and anonymous usage and crash diagnostics.
What it costs, and what else to look at
Aqumi runs on macOS 14 or later, on Apple Silicon and Intel, and takes about 25 MB. It is a one-time $2.99 purchase rather than a subscription, with a 30-day trial that needs no card and no email - the license is permanent. The full specification is on the Aqumi page.
Hydration is one of the three things a desk quietly costs you, and the other two have their own cadence. If your eyes ache by six and you sit for three hours without moving, that is Recess, which runs eye-rest and stretch timers on separate clocks, feature by feature in a 20-20-20 rule app for Mac. There is a wider look at both in desk health apps for Mac.