KoiLog: Koi Pond Tracker

KoiLog is the private, offline-first logbook for backyard koi keepers. No account. No cloud. Yours forever.

Everything you track in a notebook, done properly:

WATER TESTING
Log temperature, pH, ammonia, nitrite, nitrate, KH, GH, salt, dissolved oxygen and TDS in seconds. Charts with koi-safe range bands show trends at a glance.

FEEDING GUIDE
KoiLog reads your latest water temperature and tells you exactly how to feed — from winter dormancy (do not feed) to summer growth feeding. Koi are cold-water fish, and KoiLog covers the whole year.

YOUR KOI COLLECTION
A profile for every fish: variety, photos, growth measurements with length/weight charts, source, value and status. Watch your tosai grow into jumbo.

MAINTENANCE & TREATMENTS
Recurring tasks with reminders — water changes, filter cleans, UV bulbs. Log salt or medication treatments with an active day counter. The built-in salt calculator doses therapeutic salt correctly for your pond volume (salt is an optional treatment — koi are freshwater fish).

PRIVATE BY DESIGN
Everything stays on your device. No sign-up, no subscription required, no tracking. Export your data to CSV anytime.

FREE: 1 pond, 5 koi, 3 tasks, 30 days of charts, salt calculator and feeding guide.
KOILOG PRO: unlimited everything, full history, collection stats and CSV export — one-time lifetime purchase or monthly.

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://koi-log.com/privacy.html