Aquarium Water Log

Aquarium Water Log is a simple, fast way to record and track the water chemistry of every tank you keep — freshwater, saltwater (FOWLR), or reef.

Stable water is what keeps fish and corals healthy, and most trouble shows up in the numbers before it shows up in your livestock. This app makes logging a test quick enough to actually do it every time, and turns your readings into trends so you can spot a problem while it's still easy to fix.

WHAT YOU CAN TRACK
• pH, temperature, ammonia, nitrite, nitrate
• KH / GH for freshwater
• Salinity, alkalinity, calcium, magnesium, phosphate for saltwater and reef
• Each tank shows only the parameters that matter for its type

BUILT FOR REAL TESTING SESSIONS
• Add as many tanks as you like, each with its own type and volume
• Log a full set of readings in seconds, right after you run your test kit
• Skip any parameter you didn't test — nothing is forced
• Add a note to any reading

SEE THE TREND, NOT JUST THE NUMBER
• Per-parameter trend charts with the recommended target range shaded in
• Instantly see whether a value is drifting toward trouble
• Full reading history per tank, with out-of-range values highlighted

YOUR DATA STAYS YOURS
• Works completely offline — no account, no sign-up, no cloud
• Everything is stored locally on your device
• Export any tank's readings as CSV to keep your own backup or open in a spreadsheet

Whether you run a single planted tank or a row of reef systems, Aquarium Water Log helps you stay ahead of water-quality problems instead of reacting to them.

This app is free and supported by ads.