Your aquariums, always in balance.

Open the Tanks tab and tap “Add tank”. Give it a name (e.g. “Reef 300L”), pick the water type (freshwater, brackish, saltwater, reef) and — if you need it — add the setup features, such as Planted. Then save: Gurglee already suggests the right parameters and target ranges for that kind of aquarium, so you can start right away.

The water type is a single choice, features add to it: a heavily planted freshwater tank is “Freshwater” + “Planted”, not one instead of the other.

When you create a new tank, Gurglee offers setup mode: a short wizard that walks you through the nitrogen cycle, the 4-8 weeks a tank needs to “mature” before it can host animals.

It explains the three stages (ammonia peak → nitrite peak → nitrate), asks a few questions about your tank (new or seeded water, with or without fish, live/dry rock or DSB for saltwater) and proposes the right reminders. The tank then shows a cycle card that reads your readings and tells you where you stand — celebrating milestones and telling you clearly when it's ready for its first guests. You can also start it later from the tank menu, and finish it whenever you like. The wizard, the cycle card and the milestones are free; the automatic reminders, the comparison chart (your cycle vs the typical curve) and the fishless ammonia-dose calculator are Premium.

Go to the Measure tab and type naturally, e.g. “calcium 420 in the reef” or “kh 7.8”. Gurglee recognises parameter, value, unit and tank, converts to the reference unit and shows you its interpretation with a confidence score. Confirm with a tap and it's saved. Everything runs on-device, even offline.

Yes. In the Measure tab tap the microphone icon and dictate the value (e.g. “nitrate twenty in the freshwater”). Voice recognition is the operating system's on-device engine; the recognised text goes through the same parser as typed input. It needs the microphone permission. Where dictation isn't available (e.g. Windows) the app tells you and you can type instead.

Open a tank and tap a parameter: you'll see the trend chart with the target band highlighted, the analysis (min, average, max, last change) and the last 5 readings. The rest are one tap below, under “See all readings”, which opens the Reading history.

The tank dashboard shows at a glance how many parameters are balanced and which are out of range, with an alert when a value leaves the limits you set.

In the Reading history: all your readings together, grouped by day and, within a day, by parameter. You can get there from three places:

• the Measure tab, via the “Reading history” card at the bottom (all tanks);
• the tank menu, already filtered to that tank;
• “See all readings” under a parameter's chart, already filtered to that tank and parameter.

At the top you'll find filters for period (last 7, 30, 90 days, all time, or a custom date range), parameter (more than one at a time) and tank. The parameter chips only list the ones you have actually measured. Tap a row to open that reading and correct or delete it.

Open the tank, tap Tank menu and choose Parameter card. The app builds an image with the latest reading of every parameter you track and lets you share it wherever you like: WhatsApp, a Facebook group, a forum, stories, or saved to your gallery.

The card is meant to be read by someone who doesn't have the app: every value carries its unit, your tank's target range and an arrow showing whether it is rising or falling compared with the previous reading. Values outside the range are marked in words too, not only by colour. A reading older than two weeks shows its own date, so nobody mistakes it for today's.

Before sharing you can leave out the tank's name, its inhabitants or the target values: the choice is remembered for next time. Hiding the targets does not hide out-of-range values — those stay marked, because they are what people are about to answer about.

The preview you see is the image that gets shared. Only what you see there ends up in it: no account data, no location. It is free for everyone, shared tanks included.

In the Activities tab tap “Add” and choose the kind: reminder, water change, fertilization, dosing or medication course. You can link a product and dose, set a recurrence (custom too) and, for medications, an end date. In the Note field you can add details that don't fit in the title (e.g. “siphon the right-hand side”, “double dose if nitrates are high”): you'll see them right on the activity card. When it's due you get a local notification on the device.

From the menu (top icon) open the Calculators: water change (with an automatic suggestion of how much to change, sump included), salt, KH and calcium. Enter the required data and Gurglee tells you how much to dose. They're all free and work offline.

Open a tank, tap a parameter (say Nitrate) and scroll to the “What if…” card. Pick how much to change — 10, 20, 30 or 50% — and read where the value lands: “40 ppm → ~28 ppm”, with the litres for your own tank volume and whether the prediction sits inside the range you set.

It starts from your own last reading, so there is nothing to copy by hand: that is the difference from the Calculators, which stay in the menu for sums about a tank that isn't yours. The card also names the single action that would be enough to get back in range (“to reach 25 ppm you need a change of about 37.5%”) and “Schedule it” turns that into a ready-filled activity.

For alkalinity, calcium and salinity you can switch to the Dose tab: type the grams and see where you end up, overshoot included, before dissolving the extra gram. Grams and litres need the tank volume: if you haven't set it, the card says so.

On some values no prediction appears, and that is not a bug: pH is logarithmic and held by KH and CO₂, while CO₂ and oxygen go back into balance with the air within hours. A number there would be precise and wrong, so Gurglee would rather tell you why it stays quiet. And it is a theoretical estimate in any case: always test after the job.

At the bottom of the card there is “Several actions in a row”, part of the Premium plan: several changes in sequence and, above all, how much the value climbs back in between — estimated from your own readings, and printed next to the number (“about 2 ppm a day, from 5 of your readings over 10 days”). That is the difference that matters: three 25% changes are not one 75% change, and sometimes the answer is that this route never gets there — worth knowing before doing three changes for nothing. If your readings aren't enough to estimate the rise, the screen says so instead of pretending it is zero.

Yes: Gurglee is offline-first. Your aquarium data is stored on the device and that's the source of truth. No account is required to use it. The cloud is optional and only needed if you want to sync across multiple devices.

Open the Account section (profile icon) and sign in with email and password, with Google, or — on iPhone and iPad — with Sign in with Apple. With an account you can start cloud sync. For your first 14 days after signing up it is automatic for everyone: whatever you log goes up on its own. After that, on the Free plan it becomes manual (“Sync now”), while on Premium it stays automatic in the background. Your local data remains the source of truth, so the app works in full even with no connection.

Yes. On first launch Gurglee shows a short run of cards explaining how the app is laid out: where you create a tank, what the four bottom tabs are for, and where the AI lives. You can skip it at any point with the button in the top right.

Two helpers stay behind afterwards. At the top of the tank list you'll find “First steps”, a small checklist that ticks itself off as you create your first tank, log your first reading, set a reminder and try the Assistant; it disappears once complete, or you can close it with the ✕. And the first time you reach a spot that isn't obvious — the tank menu, the dictation microphone — a callout points it out: “Got it” closes it, “Skip” turns them all off.

To replay it: Tools menu (the grid icon at the top) → Tutorial, or Account → Replay the tutorial. It starts again from the first card and the callouts come back.

When an important new feature ships, the tutorial updates itself: instead of replaying the whole run you'll just get the callout for what's new, with a “New” tag next to the title.

It's an AI-assisted diagnosis (Premium feature): from the tank menu open Tank doctor, describe the problem in your own words (e.g. “green hair algae on the glass for two weeks” or “the fish breathes fast at the surface”) and the AI replies with hypotheses ranked by likelihood, useful questions and concrete steps. It's a chat: if the doctor asks questions you can reply and refine the diagnosis, and the conversation is saved on your device.

What sets it apart from a generic AI is that Gurglee knows your tank's history: it automatically attaches a summary of your data (recent parameters, out-of-range values, activities) so the advice fits your case. It's opt-in with a dedicated consent and off by default (you can revoke it from your account) and it only answers about fishkeeping (it is not a general-purpose assistant). It is not a vet: these are hypotheses to verify; for serious illness consult an expert.

Transparency (AI Act): answers are AI-generated and labelled “AI-generated” — you are interacting with an AI system, not a person. At the top you can see how many diagnoses you've made today (e.g. “Today 3/15”: an anti-abuse cap, not a quota); if the service is temporarily unavailable you can tap “Retry”.

All conversations are saved on your device: open “Past diagnoses” to review previous ones or start a new chat without losing the old, and long-press a message (or tap the copy icon) to copy it.

The AI assistant (a Premium feature) is the Assistant tab at the bottom of the screen: ask it anything about fishkeeping in general — “how often should I change the water in a reef?”, “what light do SPS need?”, “how do I pick a filter?” — and it answers in plain words, with a few practical tips and follow-up questions you can tap.

How it differs from the Tank doctor: the assistant answers in general, the doctor diagnoses your tank. If something is wrong in there — algae, sick fish, odd readings — go to the Tank doctor (from the tank menu, or from the button inside the assistant): it reads that tank's recent parameters, out-of-range values, inhabitants and activities, and suggests hypotheses ranked by likelihood.

What gets sent: your question and, at most, your tanks' profile (name, type, volume, age) — never your readings or logbook, which only the doctor needs. It uses the same consent as the doctor (opt-in, off by default, revocable from your account) and only answers about fishkeeping.

One daily limit: assistant and doctor share the same anti-abuse counter — the one shown at the top (“Today 3/15”) is the total of both, not two separate allowances.

Transparency (AI Act): wherever the “AI” mark appears in the app, artificial intelligence is involved, and answers are labelled “AI-generated”. They are general guidance to verify. For questions about how the app works, these FAQ answer for free, without using AI.

Yes: your first 2 questions are free, with no subscription and no card. They cover the AI Assistant and the Tank Doctor together — two tries in total, not two per feature — and they don't reset the next day: they're there to show you how they work on your own tank data before you decide.

How many are left is shown in the badge at the top of both screens. You still need an account (the count belongs to it, not to the phone) and the consent to send data to the AI features, which is asked the first time.

The Assistant's ready-made answers — the most common questions, already written inside the app — don't use up tries: they call no model and work offline too.

Once the two tries are gone, the AI stays available with Premium, which has a daily usage limit shared between the two features.

Android: Gurglee is on the Google Play Store — play.google.com/store/apps/details?id=app.gurglee. It's free, and you don't need an account to start: the Free plan runs entirely on your phone.

iPhone and iPad: Gurglee is on the App Store — apps.apple.com/app/id6795946757. Same deal: free, and it works without an account too.

On any other device (computer, tablet) you can use Gurglee straight from your browser at app.gurglee.app, with nothing to install. From a phone browser you can also add it to your Home screen (“install app”): it then opens full-screen like a regular app.

Windows: the native version is on the way. In the meantime the web version does everything, with two OS-related exceptions: reminder notifications and voice dictation only work in the native apps.

Your data moves between devices only if you sign in with an account: without one it stays on the device where you entered it (see the entry about accounts and syncing).