About
AquaPi for ESPHome bridges the gap between the aquarium hobby and the smart home ecosystem. Built on ESPHome firmware and Home Assistant, it transforms any aquarium setup into a fully monitored, automated environment using low-cost, open-source hardware and software. At its core, AquaPi runs on an ESP32 DevKit microcontroller and integrates with Atlas Scientific EZO circuits to deliver high-accuracy measurements of pH (0–14 range, ISO 10523 compliant), conductivity/salinity (EZO-EC, ISO 7888 compliant), dissolved oxygen, oxidation-reduction potential (ORP), and CO₂ in air. It also supports temperature via Dallas DS18B20 waterproof probes, water level optical sensors, and water leak detection. Additional capabilities include automated dosing via the EZO-PMP peristaltic pump (0.5–105 ml/min), wireless OTA firmware updates, and an optional built-in web server for device management without Home Assistant. All sensor data flows seamlessly into Home Assistant dashboards for visualization, alerting, and complex automations. The system is fully open-source and modular: users can start small and expand sensor arrays or add actuators over time. Pre-built firmware can be flashed directly from the browser via USB, and a comprehensive wiki covers calibration, circuit diagrams, and advanced configuration. Community support is available through Reef2Reef forums, and complete builds or modular components are available for purchase for those who prefer a ready-made solution. AquaPi is ideal for reef tank keepers, freshwater hobbyists, aquaculture operators, and smart home enthusiasts who want full control and visibility over their aquatic environments at a fraction of the cost of commercial alternatives.
Key Features
- Comprehensive Water Parameter Monitoring: Measures pH, salinity, dissolved oxygen, ORP, CO₂, temperature, and more using Atlas Scientific EZO circuits with laboratory-grade accuracy.
- Home Assistant & ESPHome Integration: Seamlessly connects with Home Assistant for rich dashboards, alerts, and automation rules, leveraging ESPHome for firmware management and local control.
- Automated Dosing via Peristaltic Pump: Controls the EZO-PMP peristaltic pump for precise liquid dosing of chemicals or nutrients at flow rates from 0.5 to 105 ml/min.
- Modular & Expandable Hardware: Add new sensors, probes, and actuators over time. Supports leak detection, water level sensing, humidity, RTD temperature, and custom automations.
- Wireless OTA Updates & Web Server Access: Update firmware over-the-air via ESPHome and manage your device through the optional built-in web server—no Home Assistant required for basic access.
Use Cases
- Reef tank monitoring for saltwater aquarists who need to track pH, salinity, and ORP in real time to maintain coral health.
- Freshwater planted aquarium CO₂ and temperature automation to optimize plant growth and fish wellbeing.
- Automated chemical dosing for reef tanks using the EZO-PMP peristaltic pump to maintain stable alkalinity, calcium, and magnesium levels.
- Aquaculture and fish breeding operations requiring continuous dissolved oxygen and temperature monitoring with automated alerts.
- Smart home integration for aquarium enthusiasts who want to unify tank monitoring with Home Assistant automations, dashboards, and mobile notifications.
Pros
- Truly Open-Source & Free: Fully open-source with no licensing fees—anyone can use, modify, and contribute to the project, making it far more affordable than commercial aquarium controllers.
- High Sensor Accuracy: Uses industry-standard Atlas Scientific EZO circuits compliant with ISO standards, delivering reliable, lab-grade water quality measurements.
- Deep Home Assistant Integration: Natively integrates with Home Assistant for powerful automations, notifications, and data visualization using a well-known, widely supported smart home platform.
- Modular and Scalable: Start with one sensor and expand progressively—the system is designed to grow with your aquarium setup and unique monitoring needs.
Cons
- Requires Technical Setup: Initial setup involves configuring ESPHome, Home Assistant, and hardware assembly, which may be challenging for users without technical backgrounds.
- Depends on Raspberry Pi / Home Assistant Infrastructure: A Home Assistant instance (ideally on a Raspberry Pi 3+) is required for full functionality, adding to the total hardware cost and complexity.
- Sensor Probe Replacement Costs: Atlas Scientific probes have finite lifespans (e.g., pH probes last ~2.5 years, ORP probes ~2 years), leading to recurring replacement expenses.
Frequently Asked Questions
What hardware do I need to get started with AquaPi?
You need an ESP32 DevKit microcontroller, a Home Assistant device (Raspberry Pi 3 or higher recommended), a reliable 5V 3A power supply, and the Atlas Scientific EZO sensor circuits for the parameters you wish to monitor.
Is AquaPi really free to use?
Yes. AquaPi is fully open-source and free to use, modify, and distribute. You only pay for the physical hardware components (ESP32, sensors, probes). Pre-built units are also available for purchase if you prefer not to assemble it yourself.
What water parameters can AquaPi monitor?
AquaPi supports monitoring of pH, salinity/conductivity/TDS, dissolved oxygen, ORP, CO₂ (gaseous), temperature (Dallas DS18B20 and EZO-RTD), humidity (EZO-HUM), water level, and water leaks.
How do I install the AquaPi firmware?
You can flash the pre-built firmware directly from your browser via USB without any additional software. Once installed, future updates can be delivered wirelessly using ESPHome's built-in Over-the-Air (OTA) update feature.
Can I use AquaPi without Home Assistant?
Basic device management is possible through AquaPi's optional built-in web server without Home Assistant. However, for full automation, visualization dashboards, and alert capabilities, Home Assistant is strongly recommended.
