Coming soon to iPhone and Android
Your pond's whole story, in your pocket
Log your water, keep a record of every koi, and never forget the pond chores — all in one app built for koi keepers.
14-day free trial · Explore a sample pond without an account
Features
Everything your pond needs you to remember
Test kits, notebooks, phone photos and sticky notes on the fridge, all brought together. KoiKeep keeps the whole picture in one place, so you can spend less time keeping records and more time watching your fish.
See trends, not just numbers
Log pH, ammonia, nitrite, nitrate, phosphate, KH, salinity, and water and outside temperature. A chart shows how each reading moves over time, so a slow drift gets noticed before it becomes a problem.
Know when you last tested
The Home screen shows how long it has been since your last water check. It gives you a nudge after a week and a clear warning after a month.
A record for every koi
Give each fish a profile with its variety, photos, a short video clip, birth and purchase dates, what you paid, and your notes. Keep a wish list of the koi you're still hunting for, too.
Routines that repeat themselves
Set reminders for water changes, filter cleaning, treatments and feeding changes. Repeat them every few days, weeks, months or years, colour-code them by category, and see what's due on the Home screen.
A journal with context
Write observations and attach them to the water test you took that day. Save pond photos and videos as memories, so you can look back on how your pond and your fish have grown.
Learn as you keep
Read care articles that cite their sources, look up koi terms in the glossary, and browse a variety catalog with photos from Genki Nishikigoi. The built-in calculators handle salt doses, pond volume and free ammonia.
How it works
From first test to full history
There's no long setup. Add your pond, log what you already test, and KoiKeep builds the history for you.
Try the sample pond
Open KoiKeep and explore a ready-made sample pond with readings, journal entries and memories. You don't need an account.
Add your pond
Sign up with email, Google or Apple, then add your pond's name, size and location. Your 14-day free trial starts here.
Log as you go
Record each water test, add your koi, and set reminders for your routines. Every entry adds to a history you can look back on.
Made for pondside use
Watch the rhythm, not just a single number
One reading tells you about today. A season of readings tells you how your pond really behaves. KoiKeep puts your latest results next to the trend, so you can see what's normal for your water and spot what isn't.
- Choose which readings appear on your Home screen and pond summary
- Fahrenheit or Celsius, gallons or litres, with more than one pond if you have them
- Light and dark mode, so it's easy on the eyes at dawn feeding or a late check
How much does KoiKeep cost?
You get a 14-day free trial when you create an account. After that, it's $17.99 a year in the US, billed through the App Store or Google Play. Local prices are shown in the store. You can explore the sample pond, the care articles and the calculators without an account at all.
Which devices are supported?
KoiKeep is coming to iPhone and Android phones. One account works on both, so your records follow you if you switch phones.
Can I track more than one pond?
Yes. Add as many ponds as you keep, each with its own water log, koi, journal, memories and reminders, and switch between them from the menu.
Who can see my koi and photos?
Only you. Your records are private to your account, and your photos and videos are kept in private storage that no other user can open. KoiKeep has no ads, and we never sell your data.
How is my data handled?
Your records are stored securely with our hosting provider and used only to run the app for you. The full details are in our Privacy Policy. You can delete your account and everything in it at any time, right inside the app. The data deletion page shows how.
How do I get help?
Visit the support page and email us. KoiKeep is made by an independent developer who reads every message.
Coming soon to the App Store and Google Play
KoiKeep is almost ready. When it launches, start your 14-day free trial and give your pond the record it deserves.