reefnotes
Your quiet aquarium logbook for the small daily rituals of the hobby.
For anyone keeping a tank, or just planning one. Every test, every dose, every water change in one place. Visualising your readings flags the slow drifts long before you notice them in the tank.
Free. Ad-free. Yours.
Works in any browser — iPhone, Android, laptop. Nothing to install.
When the readings start to climb
The tank runs quietly in the background. When your readings start to wander — not just spike once — reefnotes helps. Together we spot the pattern before it becomes visible.
Groundhog Day, in the good way
Water changes, fertiliser doses, water tests — all in one place. What's due today? We'll show you. And if you can't be bothered, it's still there when you come back.
As private as a notebook
Free. No ads. No trackers. Your readings stay yours — not sold, not analysed for someone else, and always there for you.
Two snails looking into your tanks with you
Manfred has the calm of someone who has seen many water changes. Stormy is new, eager, and watching everything. They do not live in chat bubbles. They are simply there when you open the logbook — Manfred with patience, Stormy with wide eyes.
Manfred remembers all the small details of your tanks
Manfred remembers every test, every dose, every water change. Years of readings stay in one place, sorted by tank and parameter. When you wonder, “Did I fertilise last Sunday?” — Manfred has the answer.
Stormy notices the smallest changes
Stormy is eager, but watchful. She notices when your readings don't just spike once but really start climbing. When your pH or KH begins to rise, she gives you a small nudge — not loud, just early enough.
A long memory for a slow hobby.
Today first. Everything else, below.
Open a tank — what's due today is the first thing you see. Water changes, tests, doses, lined up at the top. Four big buttons next to the list log what you just did. Older days drop into the monthly calendar below; forgot yesterday? Open the day, mark it done, skipped, or 'I'll get to it tomorrow.'
First time on a tank? Both mascots show you around.
The first time you open a tank, Manfred and Stormy take turns spotlighting each part of the page — what's due today, your water values, the trends chart, the suggestions, the setup shelf. Skip whenever you want; replay anytime from the top of the page.
Every parameter, every tank, on one page.
Freshwater, reef, planted — same logbook, same cards. Each parameter shows the current value, its drift rate, and how long it's been in its target band. A glance, not a deep-dive — unless you want one.
The slow drifts, finally visible.
Months of measurements at a glance, water-change markers along the way, and a cycle forecast showing where the values are heading. So you can finally see whether the nitrate is really climbing — or it just looks that way on a Sunday morning.
Your whole tank, one wide table.
Every water change, test, and dose as a row — newest first, parameters across the columns, just like the spreadsheet you probably already keep. Edit any cell in place: correct a reading, add one to an old entry, fix a date. Export the lot to CSV whenever you like.
Show off the tank you keep.
Flip a switch and your tank gets a clean public URL — just the water values and the photo, no doses, no notes, no location. Drop the link in a forum signature or send it to a friend. Off by default; one click to turn it on, one click to turn it off.
Dosing that listens to your last water change.
The suggestions know what you just changed out, what your tap brings back, and what your last test said. Top up what's running low. Pause what's stacking up. Skip the math.
Same logbook. Beginner's pace, or pro's.
If this is your first tank, Manfred and Stormy walk you through the nitrogen cycle and what to test when. If you've kept tanks for years, skip the tour and drop straight into the data — every chart, every formula, every parameter, with the band edges and the rates you'd write down by hand.
Stormy is new here too.
You don't need a chemistry degree or three forum threads. Stormy is standing in front of her first tank too — together you'll learn the nitrogen cycle.
- Nitrogen-cycle guide with a four-step checklist.
- First-steps tour: first reading, tap water, water-change rhythm.
Manfred has been at this a while.
A logbook you can trust with a five-year reef — formulas and units the way you'd write them on paper.
- Per-parameter trends across years, with water-change markers.
- Pro mode: NO₃⁻, PO₄³⁻, K⁺, Ca²⁺, real formulas.
From one aquarist to another.
I keep a few tanks myself, and I got tired of every aquarium app trying to be everything — a forum, a marketplace, a notification machine, a paywall. So I built what I actually wanted: a logbook anyone can understand. Water tests, doses, water changes, sorted by tank and parameter, with the effects underneath. No forum. No marketplace. No paywall. Free, ad-free, yours. If you keep a tank — or you're just curious — pull up a chair.
A personal side project of foxigit, reefnotes lives in the small daily rituals of the hobby — a water change here, a fertiliser dose there, a quick water test before bed.
Aqua Rebell® and JBL® are trademarks of their respective owners. reefnotes is an independent project — not affiliated with, endorsed by, or sponsored by these companies.