Limno: Aquarium & Fish Tank

Aquarium water test tracker, fish compatibility checker and nitrogen cycle assistant for freshwater, planted and shrimp tanks.

Keep your fish healthy and your plants thriving. Limno turns your own water test results into early warnings, step by step cycling guidance and clear answers about which fish and shrimp fit your tank.

WHAT LIMNO DOES FOR YOU
• Ammonia toxicity, worked out for your tank. Your test kit measures total ammonia. Limno estimates the toxic free ammonia (NH3) from total ammonia, pH and temperature, so you can tell when to worry and when not to.
• Alerts that understand your tank. Limno watches how fast your values change and takes your tank setup into account. Every alert tells you the likely cause and what to do now. Planted tanks with CO2 injection do not get false pH alarms.
• A cycling assistant that guides you. Fishless or with fish, Limno reads your ammonia, nitrite and nitrate tests, shows which stage your nitrogen cycle is in, what to do today, and why a cycle has stalled.

WATER TEST LOG
• Track pH, KH, GH, ammonia, nitrite, nitrate, phosphate, temperature, TDS, iron and copper.
• Log a whole test session in seconds with presets and a built-in number pad.
• Add old results from your paper notebook with their original dates.
• Charts show water changes, dosing and new fish as markers, with the ideal range for the species you keep.

FISH, SHRIMP & SNAIL GUIDE
• 220+ popular freshwater species you can actually find in stores.
• Search by common name in many languages or by scientific name, with or without accents.
• Temperature, pH, GH and KH ranges, adult size, temperament, school size and minimum tank size.
• Filter by fish, shrimp, snails, easy to keep, or species that fit your tank.
• Missing a species? Add your own and keep going.

FISH COMPATIBILITY CHECK
• See if a new species fits your aquarium before you buy it.
• Checks water parameter overlap, aggression, fin nipping, fish that eat shrimp or snails, territory, school size and tank size.
• Stocking level shown as a range, so you know when your tank is getting crowded.

CARE & REMINDERS
• Water changes, filter cleaning, fertilizer, feeding, trimming and your own tasks, every few days or on chosen weekdays.
• Get reminded on time, then mark a task done, snooze it or skip it right from the notification.
• Home screen widget with today's aquarium tasks.
• Finished tasks appear on your charts, so you can see what changed your water.

8 AQUARIUM CALCULATORS
• Tank volume with the real water volume, minus glass, substrate and hardscape.
• Water change mixing with tap and RO water, target GH and KH, nitrate reduction, CO2 from pH and KH.
• Salt, water conditioner and medication doses as a safe range, to check against your product label.

PRIVATE & OFFLINE
• No account, no sign up. Everything works offline, even in airplane mode.
• Your tank data stays on your device.
• Metric or US units, light and dark mode, phone and tablet.
• Species data updates automatically.

MADE FOR FRESHWATER KEEPERS
Planted tanks, aquascapes, community tanks, betta and shrimp tanks. Whether you are setting up your first aquarium or running a high tech planted tank with CO2, Limno helps you read your water and act in time. Limno is built for freshwater aquariums only and does not cover saltwater or reef tanks.

Set up your first tank in under a minute and log today's water test.