What is Marine Assistant?

Marine Assistant is a DIY Reef Monitoring and Automation system. With the Marine assistant you can connect a wide range of sensors and probes, enabling you to automate many tasks of your reef tank.

What can it monitor?

Water levels with float or optical sensors
Temperature
Water leaks
PH, TDS, EC and ORP
Power usage

What can it Control?

12v Devices directly, LEDs for alarms, 12v solenoid valves...
240/120v equipment using standard smart plugs

Using the Information gathered from the various sensors you can create various automations. Create your own ATO or turn your return pump off if a leak is detected...

Designed to be easy to assemble requiring minimal tools, the Marine assistant is cost affective and can be assembled by almost anyone! Click "Learn more" to see what skills are required to build one...

Learn More

Kits are available here in the store, many options available. Either a complete kit with selected components or just the PCB. You decide...

Get Yours here

What does it do?

Marine Assistant lets you monitor and automate your reef aquarium using Home Assistant. With our hardware, you can easily control lighting, temperature, pumps, dosing, water levels, and more - all from your mobile device or computer.

Set routines, get alerts, and keep your tank stable wherever you are. It's a powerful tool for creating a smarter, more reliable reef setup with less effort.

Whether you're at home or away, you’ll have full visibility and control over your aquarium environment. Marine Assistant gives reef keepers the tools to build smarter, more reliable tanks—with total flexibility.

The vision for Marine Assistant

With Marine Assistant, We wanted to create something that was easy to build without compromising on features. While testing other reef computers, we noticed room for improvement. The first was the price—many of them come at a premium cost, making them inaccessible to some hobbyists. The second was the lack of third-party sensor compatibility.

Marine Assistant is designed to work with a wide range of manufacturers. Whether you want to spend €30 on a pH sensor from eBay or €200 on a lab-grade sensor, Marine Assistant can be adapted to work with both. You're not locked into any specific sensor system—use whatever works best for you. That being said we provide some recommendations for analog sensors that our guides are based on.

By using Home Assistant for the software, Marine Assistant benefits from continuous development and updates. Home Assistant is a widely used and well-supported automation platform, making it perfect for this application. You can create your own automations and dashboards easily, customizing them exactly how you want. Everything runs locally on your home network, so no cloud service is required (One is however available).

We've also created step-by-step online guides to walk you through the entire process—from building the hardware to installing and setting up the software, adding sensors, configuring automations, and customizing your dashboard.

We are constantly developing this project, working on new hardware and improving the software. With many ideas for the future, including lighting control, dosing pumps, and more.

Explore

How much does a set-up cost?

One of the biggest advantages of Marine Assistant is the cost savings compared to the competition—leaving you with more money for livestock.

Here’s a breakdown of the approximate cost of the parts needed to build a basic setup. This setup includes:

Three float switches and an optical sensor for an ATO (Automatic Top-Off).
Two temperature sensors.
A pH sensor and an EC sensor to monitor pH and salinity.
Six mains voltage smart plugs to control your return pump, lights, skimmer, heater, powerheads, and media reactors.

Items	Price (€)	Price ($)
Marine assistant kit	100€	115$
Raspberry Pi	80€	90$
ESP32	5€	6$
Temperature sensors (2x)	15€	17$
Smart plugs (6x)	50€	56$
PH sensor (1x)	45€	50$
EC Sensor (1x)	85€	95$
Float switches (3x)	5€	6$
Optical sensor (1x)	15€	17$
Wire / Other parts	20€	25$
Total	420€	477$

All prices are estimates and serve only as a guide to the potential cost of a simple but complete setup. The final price may vary depending on the type and number of sensors you choose.

Essential Skills Can you build one?

Don’t worry—putting everything together is straight forward, even if you don’t have a lot of experience. While a few standard tools are required, the process is simple and manageable. To make things even easier, we’ve put together a wide range of detailed guides and resources right here on the website. Whether you're starting from scratch or just need a quick reference, you'll find all the support you need to get the job done with confidence.

Tools you will need:

Soldering Iron (Tip should be about 1mm, not too big)
Solder (Its better to use a good quality one with flux)
Solder wick or solder sucker (For clean-up)
Tape (Masking tape or similar)
Some basic tools. (Screwdrivers, wire cutters.....)
Multimeter

Optional:

Helping hands (To hold the PCB while soldering)

Need Help?

Marine Assistant is proud to have an ever-growing community of passionate DIYers who use and trust our hardware for their reef aquariums. Whether you're just getting started or tackling something more advanced, you're never alone. If you run into questions or need advice, feel free to reach out directly—we’re always happy to help. You can also connect with fellow users, share your progress, and get support through our active community group. Join the conversation and become part of the Marine Assistant network, Click below to get involved.