What Is GrowVPD Pro?

GrowVPD Pro is a free, offline-first Android app that gives you everything you need to manage indoor grows. It combines a VPD chart, a full grow diary, PPFD light guide, nutrient calculators, plant disease identification, equipment profiles, and smart device automation — all in a single 15 MB download. No account required, no internet needed for core features.

Whether you are a first-time grower or a seasoned cultivator with a multi-tent setup, the app scales from simple daily logging to fully automated climate control with Tuya, Mars Hydro, AC Infinity, and other smart devices.

Download and First Launch

Install GrowVPD Pro from Google Play. On first launch you will see a short onboarding walkthrough that introduces the main features. You can skip it if you prefer, but it is worth the 30 seconds.

The app works entirely offline. You only need an internet connection if you want to connect smart devices or share data.

The 9 Tabs Explained

The bottom bar gives you quick access to every section of the app. Here is what each tab does:

  1. VPD — Interactive VPD heatmap chart. Enter temperature and humidity to see your VPD value, color-coded by growth stage. Supports Bluetooth sensor input and smart device integration.
  2. PPFD — Light meter (using your phone camera) and a PPFD reference guide. Shows optimal light levels for each growth stage.
  3. Automation — Connect smart devices, create rooms and tents, set automation rules, and monitor your environment in real time. This is a Pro feature.
  4. Diary — Your grow journal. Log daily entries with temperature, humidity, VPD, pH, EC, nutrients, photos, and notes. Track multiple grows simultaneously.
  5. Templates — Pre-built and custom grow templates. Start a new grow from a template to save time.
  6. Nutrients — Nutrient calculator for common feeding schedules. Adjust ratios per growth stage.
  7. Plant Guide — Visual guide to plant health, deficiencies, diseases, and training techniques. Includes AI-powered disease diagnostics (Pro).
  8. Equipment — Save your tent setups, lights, fans, filters, and other gear as reusable equipment profiles.
  9. Settings — Theme, language (11 available), units, PIN lock, biometric security, connected accounts, and export options.

Setting Up Your First Grow

Head to the Diary tab and tap the "+" button to create a new grow. You will be asked for:

  1. Name — Give your grow a name you will recognize, like "Tent A - Spring 2026".
  2. Strain — Enter the strain or variety you are growing.
  3. Medium — Select your growing medium (soil, coco, hydro, etc.).
  4. Pot size — Enter the container size so the app can estimate water needs.
  5. Light type — Choose your light (LED, HPS, CMH, etc.).
  6. Start date — The app defaults to today, but you can backdate if your grow already started.

Once created, your grow appears in the diary list. Tap it to start adding entries.

Tip: Use the Templates tab to start from a pre-built grow plan. Templates include suggested feeding schedules, stage durations, and target VPD values.

Adding Your First Entry

Inside your grow, tap "Add Entry" to log a new day. The entry form includes:

  • Temperature and Humidity — Enter your readings. The app calculates VPD automatically.
  • Growth Stage — Select seedling, vegetative, or flowering. This adjusts VPD targets on the chart.
  • pH and EC — Track your water or nutrient solution quality.
  • PPFD — Log your light intensity reading.
  • Nutrients — Record what you fed and how much.
  • Photos — Attach photos directly from your camera or gallery. Take regular photos to build a visual timeline.
  • Notes — Freeform text for anything else: observations, changes, reminders.

After saving, you will see the entry in your grow timeline with the VPD value highlighted in green, yellow, or red depending on how close you are to the target range.

VPD Chart Basics

Switch to the VPD tab to see the interactive heatmap. The chart shows VPD values across a range of temperatures and humidity levels:

  • Green cells = Optimal VPD for the selected growth stage. This is where you want to be.
  • Blue cells = VPD too low (under-transpiration, risk of mold).
  • Yellow/Orange/Red cells = VPD too high (over-transpiration, plant stress).

Tap any cell to see its exact temperature, humidity, and VPD value. Use the stage selector at the top to switch between seedling, vegetative, and flowering targets.

If you have a Bluetooth temperature/humidity sensor, the chart can read live data and show your current position directly on the heatmap.

Connect Smart Devices (Optional)

If you use Tuya, Mars Hydro, AC Infinity, Spider Farmer, or other supported smart devices, head to the Automation tab or Settings > Connected Accounts to link your devices. Once connected, you can:

  • See live sensor readings on the VPD chart
  • Automate fans, humidifiers, and lights based on VPD rules
  • Auto-capture timelapse photos from Tuya cameras

Smart automation is a Pro feature. Check out our Tuya connection guide or Mars Hydro connection guide for step-by-step instructions.

Tips for Beginners

Start with a template. Templates give you a proven schedule to follow. You can always customize later.
Check VPD daily. Consistent VPD is more important than hitting a perfect number once. Aim for stability within the green zone.
Take photos every day. It feels unnecessary at first, but a visual history is invaluable for comparing grows, diagnosing problems, and tracking progress.
Log nutrients and pH. When something goes wrong, having historical data makes troubleshooting much faster.

That is everything you need to get going. The best way to learn the app is to use it — create a grow, log a few entries, and explore the tabs. The interface is designed to be self-explanatory, and every feature is accessible from the main navigation.