Stablereef: Reef Tank Log

Unlimited free water logging for reef & saltwater tanks. Import your CSV history — free. 100% offline, no account, and no paywall in your core loop, ever.

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SWITCHING APPS? BRING YOUR DATA (FREE CSV IMPORT)
Tired of loggers that lock basic features behind a subscription — or of hand-typing into a spreadsheet? Import your existing history from any CSV: column mapping with automatic detection, unit conversion (dKH/meq-L, °F/°C, SG/ppt), a preview before anything is written, and a clear report of exactly what came in. Import is free forever — walking in with your own data should never cost money.

THE ANTI-SWING WARNING
Corals don't crash on a number; they crash on the swing. When you save a reading, Stablereef instantly compares it to your last value and flags anything that jumps outside your safe band — like "Alk up 0.8 dKH since last test." You catch the risky move while you're still at the tank, not buried three charts deep.
(Reference only — bands are tunable and husbandry calls are yours.)

LOG A FULL TEST IN ~30 SECONDS
A big number pad, last-value prefill, and a grid you control — pin your most-used parameters on top and hide the ones you don't track. Track Alkalinity, Calcium, Magnesium, Nitrate, Phosphate, Salinity, pH and Temperature, in the units you actually use: dKH or meq/L, °C or °F, ppt or specific gravity — without the spreadsheet that felt like a second job.

TRENDS, NOT JUST NUMBERS
7 / 30 / 90-day graphs with a shaded stability band let you separate real drift from noise and act before a small slip becomes a tank crash.

YOUR DATA IS YOURS
• Free CSV & JSON export, anytime — never behind a paywall
• Automatic local backups
• Works 100% offline — no account, no cloud, no sign-up
• Your readings stay on your device; anonymous usage stats help us improve (turn them off anytime in Settings)
Want your years of history out? One tap. We don't hold your data hostage.

FREE REMINDERS
Local notifications for dosing and testing keep you on schedule on the days you'd otherwise forget. Reminders are free — always.

THE "LESS" PHILOSOPHY
No livestock encyclopedia. No marketplace. No social feed. Stablereef does one thing — protect your tank's stability — and aims to do it better than apps juggling ten. If your aquarium app ever felt more eager to sell you fish than to keep your reef alive, this is the opposite.

PRICING THAT RESPECTS YOU
Unlimited logging, anti-swing warnings, trends, reminders, import, and export are free. No subscription, and no paywall in the middle of your core loop — ever.

PRIVACY
No account. No cloud. No ads, no cross-app tracking. Your reef data stays on your device — the only thing we collect is anonymous usage counts, with no account, no personal data and no IP address, and you can switch that off in Settings.

WHO IT'S FOR
Reef keepers who want a focused reef tank tracker instead of another do-everything app: a saltwater aquarium log for your water parameters, an alkalinity tracker that actually flags swings, and a simple coral tank log for your dosing and testing routine. If you keep a spreadsheet today, you are exactly who we built this for.

Reference tool only — not veterinary or husbandry advice. Stability bands are general references; care decisions are the keeper's responsibility.

From Sloth Lab Inc.