Comparison

WetMath vs ReefDiary

Price, ratings, monetisation and update history for both apps, side by side β€” with what reviewers say about each.

Head to head
About

WetMath

Features
Read full description

Stop guessing and start measuring. WetMath is the essential tool for freshwater and reef tank hobbyists who demand precision. Whether you’re aquascaping a new build or maintaining a delicate coral reef, WetMath provides the exact calculations you need to succeed. +1 ## Why WetMath? Built for Reefers & Aquarists: Specialized tools for salt mix adjustments, dosing, and flow rates. Simplified Planning: Calculate tank volume, substrate weight, and heater requirements in seconds. Save Money: Estimate your power costs and evaporation loss to optimize your setup. Privacy First: No accounts. No cloud. No tracking. Your data stays on your device. ## Essential Hobbyist Tools: Volume & Weight: Exact water and glass weight calculations for safety. Dosing & Chemistry: Salt mix adjustments (SG) and water weight conversions. Equipment Optimization: Pump flow, turnover rates, and heating/cooling needs. Substrate Calculator: Determine exactly how much sand or gravel you need. Operational Math: Evaporation estimators and power cost calculators. ## Universal Support Full support for both US Customary and Metric units. Designed for efficiency so you can spend less time on math and more time enjoying your aquatic life. Privacy Here is what we collect and why: App performance data: device type, OS version, app version, and coarse location derived from public IP address. This helps us understand where the app is being used, which devices are in use, and which app versions are active. This data is retained for up to 90 days on servers we control. Google Firebase Analytics: anonymized usage data, including screen views, used to understand which features are used and how often. Google Mobile Ads: the free version of the app displays banner ads. If tracking is disabled, ads may be less relevant. If tracking is allowed, ads may be more relevant. WireStix Pro removes ads. Support contact information: if you contact support, you may provide your name and email address so we can reply. We do not use support emails for tracking. Support emails are deleted when no longer needed, or within 2 years. Safety We use analytics and operational data to detect abuse, scraping, misuse, and other activity that could interfere with the app or our systems.

About

ReefDiary

Features
Read full description

Log saltwater aquarium parameters, spot stability drift, calculate dosing amounts, and keep reef care decisions grounded in your own data. KEY FEATURES: - Log Ca, Alk, Mg, pH, Salinity, Temp, NO3, PO4 in seconds - 2-part dosing calculator (BRS, ESV, Tropic Marin, custom) - Color-coded parameter cards show instant health status - Trend charts reveal drift, recovery, and repeat patterns - Exportable reports for second opinions, store visits, or support threads - Multiple tank support with separate histories and routines BUILT FOR REEF KEEPERS: - No account required, no cloud sync; reef data stays local - Works offline - practical for fish rooms and maintenance benches - Dense, scannable interface designed for daily reef checks PRO FEATURES (monthly, yearly, or lifetime): - Unlimited tanks and full long-range parameter history - Advanced dosing products and custom formulas - CSV exports and shareable reef detail images - Custom testing cadence and dosing follow-through Free to download. Pro unlocks the long view: full history, reports, formulas, routines, and unlimited reef systems. LEGAL: - Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ - Privacy Policy: https://peachuinc.github.io/legal/reefdiary/

Screenshots

WetMath4 screens
ReefDiary4 screens

Verdict

The call

The clearest difference is ads: ReefDiary at none against WetMath's shown. WetMath's advantage is update cadence (weekly vs every 4 weeks) and iOS requirement (15.6 vs 17.0). On price, in-app purchases and device support there is nothing between them.

Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS

CostPrice Β· In-app purchases Β· Ads Β· Monetization

Both are free to download. WetMath sells 2 one-off in-app purchases and ReefDiary sells 3 in-app purchases, starting at $2.99 per 7 days. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

WetMath ships an update weekly, ReefDiary every 4 weeks. The most recent releases landed on August 11, 2026 and September 10, 2026 respectively.

Scorecard3 real differences Β· 3 level
WetMath versus ReefDiary: the parameters behind the verdict, then further details
ParameterWetMathReefDiary
PriceFreeFree
Update frequencyWeekly β€” betterEvery 4 weeks
AdsYesNo β€” better
In-app purchasesYesYes
DevicesiPhone, iPad, iPod β€” betteriPhone, iPad
Requires iOS15.6 β€” better17.0
Further details β€” not scored
Size47 MB9 MB
Age rating4+4+
DeveloperNanoHawkPetr Persianov

In-app purchases

2 purchases

WetMath

One-time2
  • WetMath Pro Unlock$0.99
  • WetMathβ„’ Pro Unlock$9.99
3 purchases

ReefDiary

Subscriptions3
  • ReefTrack Pro – Weekly3 Days trial$2.997 Days
  • ReefTrack Pro – Monthly3 Days trial$7.991 Month
  • ReefTrack Pro – Yearly$29.991 Year

Questions

Is WetMath free?
WetMath is free to download, with in-app purchases available.
Is ReefDiary free?
ReefDiary is free to download, with in-app purchases available.
Do WetMath or ReefDiary have ads?
WetMath shows ads; ReefDiary does not.
Which is updated more often, WetMath or ReefDiary?
WetMath ships an update weekly, and ReefDiary every 4 weeks. Most recently, WetMath was updated on August 11, 2026 and ReefDiary on September 10, 2026.

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