A calmer way to keep your reef

Less guesswork.
More little ocean.

Water tests, saltwater math, and everyday routines. A clear, comfortable home for the details that help you care for your reef.

Explore the demo ↗See what’s included

Read-only sample tank. No account needed to look around.

◈   app.CaptainsLog · OverviewSAMPLE TANK
A little clarity for your little ocean.
Salinity
35.0 ppt
Temperature
78.0 °F
Nitrate
7.6 ppm
Ammonia
0.00 ppm
AMMONIA TREND10 sample tests
Illustrative readings, not aquarium targets or live measurements.
Take a closer look at the dashboard →
Water trendsSaltwater calculatorsEquipment presetsReusable routinesPortable records
The useful stuff, together

Core tools.
Room to breathe.

Keep your next test, water change, and maintenance day in one place. Start with the tools you need and fill in the details as you go.

01 / KNOW YOUR WATER

Record a test. See the pattern.

Log one parameter or a full test panel. Keep units clear, choose your own ranges and testing rhythm, and find past readings without the scroll.

  • Individual tests & full panels
  • Unit-aware trends & personal ranges
  • Salt-mixing & RO/DI calculations
02 / FIND YOUR RHYTHM

A little less to remember.

Reuse checklists, track completed care, and keep supplies and future ideas organized. Make the routine fit your tank.

  • Testing & acclimation checklists
  • Maintenance & replacement dates
  • Categorized shopping & materials
03 / KEEP THE WHOLE STORY

More than a set of numbers.

Save manual flow and lighting presets. Follow livestock, coral, and anemone observations in the same journal as your tank events.

  • Editable equipment preset library
  • Livestock & observation records
  • JSON backup & assistant handoff
A simple everyday rhythm

Test. Notice. Keep going.

01

Capture the moment.

Log a reading or tank event while it’s fresh. Add a note when a number needs context.

02

Look back with clarity.

Use trends and observations to see what changed, rather than relying on memory.

03

Prepare for what’s next.

Plan a salt batch, revisit a checklist, or see which materials need attention.

Meet the dashboard

Take a look around.

Explore a fictional sample reef, try the calculators, then open the demo’s Gallery view to play Currently Swimming. The public demo can’t change anyone’s aquarium records.

Open the read-only demo ↗

Sample data only · Saving disabled · Manual equipment records