"Your test kit tells you where the tank is. Reeflog tells you what to dose, whether it worked, and how stable you really are - in one loop, on your phone." Reeflog is a water-testing and dosing tracker for reef and saltwater aquariums. I built Reeflog because reefkeeping is a weekly test-dose-retest cycle, and the apps I tried just stored the numbers - then sent me to a web calculator and a spreadsheet to actually decide anything. Reeflog closes that loop. THE LOOP - Log a test in two taps with big, wet-hands steppers tuned to real kit resolution (Hanna, Salifert, Red Sea, API). - If a parameter drifts out of band, a dose card shows the exact amount of YOUR additive for YOUR net water volume - with a safe daily-change cap, so a large correction becomes a gentle multi-day plan instead of one risky dose. - Tap once to log the dose. Your next test verifies it: predicted vs measured, on target or not. THE NUMBERS REEFERS ACTUALLY WATCH - Consumption: daily alkalinity, calcium, and magnesium demand, worked out automatically from your test and dosing history - the growth and dosing-drift signal you used to need a spreadsheet for. - Stability Index: each parameter's last 30 days against its target band, condensed into one 0-100 score. The dashboard leads with stability, not last readings. Tap any score to see exactly how it is computed. ALSO IN THE BOX - Water changes with a prediction of where each parameter will land. - Calm maintenance reminders - overdue is shown gently, never a wall of red. - A livestock journal for fish, coral, and inverts, including the losses reefers track seriously, with photos. FREE, FOR AS LONG AS YOU LIKE One tank with the whole loop: all 12 built-in parameters logged and charted, the single-dose card on 5 built-in products, water changes, and the Stability Index dashboard - plus 5 maintenance tasks and 20 livestock entries. Free is a complete tank, not a demo. REEFLOG PRO - Unlimited tanks - display, frag, and quarantine, each with its own volume, dose loop, and stability. - Full chart history - pinch any parameter from one week to a full year (free shows 60 days). - Full additive database plus custom products, with safe multi-day correction plans for large changes. - Consumption analytics - daily alkalinity, calcium, and magnesium demand trended automatically. - Test Day mode - log your whole weekly panel in one screen with prior values ghosted. - Custom parameters - track anything with its own unit, range, and stepper. - Unlimited maintenance tasks, livestock, and equipment reminders. - Tank report PDF - export one tank's readings, doses, consumption, and stability to share. - ICP records with reference bands, plus an A/B coral compare slider. PRICING Pay once and own it with Lifetime ($24.99), or subscribe: $9.99/year with a 30-day free trial, or $1.99/month. All three unlock the same Pro set. Subscriptions auto-renew unless turned off at least 24 hours before the period ends; manage or cancel anytime in your App Store account settings. Any unused free-trial time is forfeited when you buy a subscription. PRIVACY Your records live on this iPhone, in your hands. There is no account to make and no sign-in, and nothing is uploaded to a server - the app works fully offline. When you want a copy somewhere else, export a tank as a PDF to share. Reeflog is an independent app and is not affiliated with any additive, salt, or equipment maker; product potencies are shown as editable references transcribed from public labels. Dosing suggestions are aquarium chemistry for your tank, not veterinary advice - always check your product's label, and correct large changes gradually. Designed exclusively for iPhone. Privacy Policy: https://app-legal-pages.vercel.app/reeflog/privacy Terms of Service: https://app-legal-pages.vercel.app/reeflog/terms