Parameters & charts
pH, KH, nitrates… 14 parameters tracked over time, with your tank type's recommended range shown in green. One glance tells you everything's fine.
Web · iOS · Android — one app
Perfect water is no longer left to chance.
AquaTender tracks your water parameters, reminds you of every maintenance task and tells your tanks' story in photos. The aquarium logbook your fish deserve — freshwater and reef alike.
No credit card · Your first tank in 2 minutes
Web browser
iOS
Android
908
species in the catalog
freshwater & reef
freshwater & reef
4,121
equipment models
listed
listed
14
water parameters
tracked & charted
tracked & charted
3
platforms
web · iOS · Android
web · iOS · Android
Features
Your whole aquarium, finally in one place
No more paper logbook, spreadsheet and photos lost in your camera roll. AquaTender centralizes your tanks' life — and warns you before things drift.
Photo log
Photograph your tanks' evolution, pick the cover photo, relive your corals' and plants' growth month after month.
Maintenance reminders
Water changes, tests, filter cleaning: checkable reminders that keep your maintenance log automatically. Nothing slips through the cracks.
Livestock & catalog
Hundreds of species listed, freshwater and reef. Instant search, add in two taps, history preserved — even departed residents stay part of the tank's story.
Equipment & inventory
Filters, pumps, lights, accessories: thousands of models in the catalog. Track what runs on each tank, and keep your setup's history.
Forum sharing
Generate a ready-to-paste post in BBCode, Markdown or HTML — public image included. Ask for advice on your favorite forum without retyping your values.
Holiday feeding plan
A feeding plan shared by a simple link with your neighbour: photos of your own tubs, doses in pinches, and they tick off what they gave. No account needed on their side.
Your tanks inside ChatGPT
Connect AquaTender to ChatGPT and just ask. It reads your readings and answers with your numbers — not with generic advice.
Planning
Plan your tank before you buy
The biggest mistake in fishkeeping: buy first, check later. AquaTender flips it — build your future population and instantly see whether it holds up.
Parameter compatibility, stocking load, minimum volume per species: you know it works before spending a cent — and before putting a fish at risk.
- Parameter compatibility — the temperature, pH, KH, GH and salinity ranges of your species are intersected: the common range is shown, or the clashing species are named.
- Enough volume? — your tank's live stocking load, and a warning as soon as a species needs a bigger tank than yours.
- No nasty surprises — test combinations, adjust quantities, decide with confidence.
Stocking plannercommunity · 120 L
12× Paracheirodon innesi
6× Corydoras panda
1× Pterophyllum scalare
Stocking load68%
- Temperature — common range 24–26 °C
- pH — common range 6.5–7.0
- Volume — Pterophyllum scalare: tank too small (min. 150 L)
The chart that talks
Spot the drift before it gets costly
Every measurement enriches the curve. The green band shows the recommended range for your tank type: as long as the curve stays inside, you're good.
Your water changes appear right on the chart — you finally see the real effect of each maintenance on your parameters.
- Smooth zoom and panning, even with years of measurements
- Recommended ranges per tank type — community, reef, shrimp…
- 10-second entry after each test, from your phone or computer
Nitrates (NO₃) — 6 monthscommunity tank 180 L
measurements
recommended range
water changes
Forum sharing
Your full tank sheet, ready to paste
One click on Share and AquaTender generates your tank's sheet: name, volume, latest parameters, photo — in your community's format.
BBCode for classic forums, Markdown for Reddit, HTML for your blog. The image is served via a secure public link: your private photos stay private.
- One-tap copy, preview before posting
- Back-link to your tank to follow the discussion
- Clean, watermark-free image with the Premium plan
Holiday feeding · Premium
Go away relaxed. Your fish will be fed.
Put together a clear feeding plan and share a single link with your neighbour or a relative. They see the photos of your food boxes, the doses in pinches, and tick off what they gave — no account, no app.
The link opens one door only: the feeding. Not your parameters, not your other tanks, not your account. And you cut it off in one tap when you're back.
- No account for the feeder — they open the link, that's it.
- Doses in plain terms — 1 pinch, 2 pellets, 1 cube… no grams.
- A shared history — nobody feeds twice.
Your feeder's pageno account
Today — WednesdayCommunity tank 120 L
Given ✓
GivenCouldn't
💬 "The key is with the neighbour. Please don't open the lid."
AI assistant · ChatGPT connector
Talk about your tanks with ChatGPT.
Connect AquaTender to ChatGPT once, then ask your questions like you would ask a fellow fishkeeper. It reads your measurements, your livestock and your maintenance schedule, and answers with your numbers — not with generic advice found elsewhere.
It also consults the AquaTender encyclopaedia: hundreds of species sheets with adult size, minimum volume and water ranges. Enough to check compatibility before buying, from sourced data rather than memory.
- Included in the free plan — read access, across all your tanks.
- You stay in control — access to your private photos is granted separately, and can be withdrawn.
- Coming soon on Premium — record a water test or a maintenance job straight from the conversation.
ChatGPTAquaTender connector
My nitrates have been climbing for three weeks on the 120 L. Should I worry?
They went from 10 to 35 mg/L between 6 and 27 July. Still below the threshold, but the slope is steady and your last water change was on 9 July. Your neons tolerate up to about 50 mg/L: a 25% change this week would be enough to break the trend.
your readingsyour maintenanceParacheirodon innesi sheet
Pricing
Start free. Stay if you love it.
No catch: the free plan is free forever, and going back to free deletes none of your data.
Free
€0 / forever
Everything you need to get going
- 1 aquarium tracked in detail
- 25 photos in your log
- Parameters, charts and recommended ranges
- Unlimited maintenance reminders
- Full catalog — species & equipment
- Forum sharing with a subtle watermark
- A discreet ad banner (in-house, no tracking)
Recommended
Premium
€2.99 / month
or €24.99 / year — 3 months free
- Unlimited aquariums — your whole fishroom
- 1,000 photos in HD quality
- Forum sharing without watermark
- Ad-free
- Shareable holiday feeding plan
- Coming soon: record tests and maintenance from ChatGPT
- Everything in the Free plan, of course
- And you support an indie project 💙
If you go back to the Free plan, your tanks and photos beyond the free quotas simply become read-only. After prolonged inactivity, your data is kept for one year before deletion (GDPR).
Frequently asked
We answer straight
Is my data mine?
Yes, entirely. Your measurements and photos belong to you, they're hosted in
Europe and are never sold or mined for advertising. GPS metadata is automatically stripped from
your photos on upload. You can request full deletion of your account at any time (GDPR).
What happens if I stop the Premium subscription?
Nothing bad: your aquariums and photos beyond the free quotas become
read-only. You lose no data, no history, no photos. Resubscribe and everything becomes
editable again instantly.
Does the app work for saltwater and reef?
Absolutely. The catalog covers freshwater and reef (hundreds of species), and the
recommended ranges adapt to the tank type: KH, calcium and magnesium for reef, GH and pH for planted
tanks, and so on.
Web, iOS, Android… is my data synced?
Yes, in real time. AquaTender is one and the same app: log a measurement on
your phone in front of the tank, find the updated chart on your computer. One account, all your
platforms.
I'm a beginner — is it for me?
It's actually the best time. The recommended ranges tell you whether your
values are healthy without memorizing anything, and maintenance reminders build the right habits
from your very first tank. The free plan covers everything a beginner needs.
What languages is the app available in?
English, French, Spanish, Italian, Dutch, German, Portuguese and Polish.
Choose metric or imperial units (°C/°F, liters/gallons) to match your preference.
Ready to dive in?
Your fish are
waiting for this.
Create your account for free and log your first measurement within two minutes. No credit card.
Start for free
aquatender.fish — the site
aquatender.app — the app
Contact
A question? Write to us.
A suggestion, an issue, a partnership idea? We read everything.