Nerite: Reef Dosing Log

Keep every aquarium stable — without the spreadsheet.

Nerite is an aquarium log, a reef dosing calculator and a maintenance reminder in one app. It works fully offline, and never asks you to sign up.

A slow drift is easy to fix. A crash is not. The difference is whether anyone saw it coming.

WATER PARAMETERS, SCORED FOR YOU
Log pH, ammonia, nitrite, nitrate, phosphate, alkalinity, calcium, magnesium and salinity. Each water parameter is checked against the target range for your system — freshwater, planted, saltwater FOWLR, reef or brackish — so you see "in range" or "out of range", not a raw number. The chart draws the ideal band behind the trend line, so stability is obvious at a glance.

THE DOSING MATRIX
Enter your current alkalinity, your target and the tank's net water volume. Nerite gives you the exact dose of soda ash, sodium bicarbonate, calcium chloride or magnesium chloride — in grams or level teaspoons — and splits it across several days when the correction would otherwise be too fast. The figures come from molar masses, not from a vendor's marketing.

WHY A DOSING CALCULATOR AND NOT A SPREADSHEET
Over-correcting is one of the most common ways to lose coral. A reef dosing calculator that hands you one large number ignores what matters: how fast the change arrives. Nerite does the alkalinity calculator maths from molar masses, checks the swing against what livestock tolerates, and spreads it over as many days as it needs. You get the schedule, not just the dose.

AQUARIUM MAINTENANCE REMINDERS
Schedule feeding, water changes, water tests, dosing and top-offs. Reminders are scheduled on your device, so they fire with no signal. Filters, pumps, lights, heaters, skimmers and ATO units each get a service interval and a visual count-down.

YOUR FOOD SHELF
Track fish food by brand and form: flake, pellet, granule, wafer, frozen, freeze-dried, nori, gel and coral food. Nerite counts down freshness from the day you opened a tub and tells you when the fish tank has a group with nothing suitable to eat.

LIVESTOCK HEALTH
Every fish, coral and invertebrate carries a health status and a permanent observation log. The symptom picker tells you what a symptom usually means and what to do first — and flags the ones that are more often water quality than disease, because reaching for a medication first is the most common way keepers make things worse.

SPECIES AND COMPATIBILITY GUIDE
250 fish, corals, invertebrates and plants, each with a photograph, care level, adult size, minimum tank size, diet and temperament. The compatibility checker flags predator-and-prey pairings, under-grouped shoaling fish, overstocking, copper-sensitive invertebrates, reef safety and temperature clashes before you buy.

BUILT FOR REAL TANKS
• Unlimited tank profiles, each with its own targets and history
• Freshwater, planted, saltwater, reef and brackish
• Full water parameter history with charts
• Water change and salinity calculators
• A living view of your tank, animated from your own stock list
• Dark, readable interface for a dim fish room
• Offline-first: no sign-up, tank data stays on the phone

EVERY KIND OF TANK
A saltwater aquarium app and a planted tank tracker in one place: parameters, targets and dosing options change with the system you pick. Freshwater keepers get a water change reminder without reef chemistry in the way.

YOUR DATA STAYS YOURS
Every reading, animal and note is stored on your device. We never receive it. The privacy policy names the few things that are: crash reports, anonymous usage statistics, and your purchase receipt.

PREMIUM
The free plan covers one tank, 30 days of parameter history, the alkalinity dosing matrix, 3 reminders, 3 pieces of equipment and 4 foods. Premium removes every limit and adds calcium and magnesium dosing plus the water-change and salinity calculators. Start with a 7-day free trial; subscriptions renew automatically and can be cancelled any time in Google Play.