Water parameters
Log alkalinity, Ca, Mg, nitrate, phosphate, pH, salinity and more — with history and traffic-light status.
Saltwater aquarium logbook
Your reef. Logged & clear.
Track water parameters, dosing, and care in one place. Works locally without an account — optional cloud sync when you want it on every device.
KH · Ca · Mg
Offline-first
Voice + AI
Built for reefers
From the first softie tank to a mixed reef — document what matters without spreadsheet chaos.
Local-first
iOS · Android · Web
Optional cloud sync
Dosing
Manage dosing heads and manual doses. Pause, resume, adjust amounts, and keep a clear timeline.
Care & water changes
Log cleaning, filter media, observations, and water changes — plus templates for one-tap routines.
Inventory & livestock
Fish, corals, equipment, and supplies with prices and shops. Keep your tank’s stock in view.
Diary, calendar, calculators
Follow activities and photos over time. Calculate salt mix, corrections, and dosing adjustments.
Voice & AI (optional)
Dictate readings or care notes. Ask the AI chat questions with your tank context in mind.
Reef does not replace professional advice. It helps you document your aquarium and keep it under control.
Your data stays with you
Reef is local-first: create tanks, log values, and work offline. Sign in only if you want backup and sync across devices.
Offline
Core logging without login
Multi-tank
Main, frag, QT — covered
Ampel
Traffic-light parameter status
EN · DE
Built for DACH reefers too
How it works
Three steps — then your tank history starts writing itself.
Create your tank
Name, type, volume, start date — so dosing and calculators know your reef.
Log what you do
Parameters, dosing, care, water changes — by tap or by voice.
See the picture
Charts, calendar, diary, and optional AI with your tank context.
Contact & support
Questions, feedback, or App Store / Play Store support — we reply by email.
We’re here
Send a message with the form. Prefer mail? Write to us at the address below — typed for humans, not scrapers.
Email:
hello
[ a t ]
nullpointer.uk
Send a message
Name, email, and your message — that’s all we need.