Stop guessing. HydroponicsCalc calculates exact nutrient doses, tracks your reservoirs, logs every grow, and gives you the data to optimise every single harvest.
Every feature is built around one principle: give you precise, actionable data with as few taps as possible.
Add unlimited grow systems and log readings from your home screen in two taps. EC, pH, temperature, and volume — all charted over time so you can see trends before they become problems.
Enter your bottle size and reservoir volume — get precise gram weights for every component, per-gallon dose rates, and a live EC estimate. No more eyeballing. No more over-feeding.
Convert between dose rates and electrical conductivity in both directions. Factor in your source water's baseline EC for readings that reflect what your roots are actually experiencing.
A photo-first timeline for each grow system. Log observations, deficiencies, feedings, and milestones with photos. When harvest arrives, export a complete PDF archive with one tap.
Vapour Pressure Deficit is one of the most critical — and most overlooked — environmental parameters for plant growth. Enter your air temperature, humidity, and leaf offset for instant, colour-coded feedback.
Calculate exactly how much pH Up or pH Down to add for any reservoir size and current reading. Calibration mode lets you tune the titration ratio to your specific adjuster concentration.
Every screen is designed for one-handed use, glanceable data, and zero learning curve.
Every calculation a serious grower needs, available offline, available instantly.
Gram-precise nutrient doses for any bottle size and reservoir volume. Supports MasterBlend, Jack's 3-2-1, GH Flora, and custom recipes.
Bidirectional conversion between dose rates and electrical conductivity. Factor in source water EC for accurate nutrient strength.
Calculate exact adjuster volumes for any reservoir size. Calibration mode tunes ratios to your specific pH Up/Down products.
Colour-coded vapour pressure deficit zones for Seedling, Vegetative, and Flowering stages. Adjustable leaf offset for accuracy.
Manage reservoir evaporation and dilution. Know exactly how much fresh water and concentrate to add after top-off.
Record wet/dry weights, calculate cost-per-gram from nutrient spend, and track energy costs from light wattage. See yield trends over time.
Log EC, pH, temperature, and volume readings for any reservoir. View trends and get change-due warnings before issues develop.
No dark patterns. No lock-in. No nonsense.
Every calculation and all your data lives on your device. No internet connection required — ever. Works in the greenhouse, the basement, or off-grid.
Zero analytics, zero crash reporting, zero third-party SDKs. We have no idea who uses the app. That's intentional and we're proud of it.
One-time purchase on the App Store. No subscription. No "Pro" tier. No features locked behind a paywall. Everything, always included.
Built with SwiftUI for iOS and iPadOS. Feels right on every screen size — from a pocket iPhone to a 13" iPad Pro on your grow bench.
Export your grow journals as PDF, harvest records as CSV. Share via AirDrop, email, or any app. Your data is yours — always portable.
Designed for growers who care about accuracy. Every calculation is based on established chemistry — no guesswork, no approximations.
Join growers who've replaced guesswork with data. Download HydroponicsCalc and take control of every variable in your grow.