DIY Aquaponics Systems: Building One With a Bathtub or Barrel

Aquaponics is an easy, sustainable way to grow fresh food, even in small spaces. One of the most affordable ways to start is by repurposing a bathtub or barrel to create a thriving system.

Whether you’re a beginner or just looking for a low-cost DIY option, this guide will walk you through everything you need to know!

Why Use a Bathtub or Barrel for Aquaponics?

Not everyone has space for a large aquaponics setup, and traditional garden beds can be costly to maintain. Repurposing a bathtub or barrel offers a budget-friendly and space-saving solution that works well for renters, small backyards, and balconies.

Benefits of Using Recycled Materials:

• Low-cost or free – Bathtubs and barrels are often available second-hand.

• Space-efficient – Ideal for small gardens, patios, or balconies.

• Sustainable – Reduces waste by reusing existing materials.

• Beginner-friendly – A great way to learn before investing in a larger system.

How to Build a Bathtub or Barrel Aquaponics System

Materials You’ll Need:

• Bathtub or food-grade barrel (must be cleaned thoroughly)

• Fish tank (or use the bathtub itself)

• Grow media (expanded clay pebbles or gravel)

• Water pump (small, energy-efficient)

• Air pump & air stone (to oxygenate water for fish)

• PVC piping and fittings (to create water flow)

• Bell siphon or timer (to automate flooding & draining) ~ Optional

• Fish (goldfish, tilapia, or native species)

• Plants (lettuce, herbs, strawberries, etc.)

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Want to get your Eyes and Hands on the FREE Online Aquaponics Essentials Course?

This is a great free resource to really understand how aquaponics is a sustainable ecosystem that will grow your organic food is a productive way.

You learn how all the 'parts' make up the 'whole', and helps to give you the foundations of understanding aquaponics.

Sign up HERE

Step-by-Step Instructions:

• Prepare Your Bathtub or Barrel

  • If using a bathtub, ensure the drain is sealed properly.

  • If using a barrel, cut it in half—one half for the fish tank and one for the grow bed.

  • Clean thoroughly to remove any chemicals or residues.

• Set Up the Grow Bed

  • Place the bathtub or barrel half on a sturdy stand.

  • Fill with your chosen grow media (expanded clay pebbles are best for easy drainage).

  • Install the bell siphon or timer to control water levels.

• Install the Fish Tank

  • If using a separate fish tank, place it below the grow bed.

  • Add water and install an air pump to keep fish oxygenated.

• Connect the Water Flow System

  • Use PVC pipes to circulate water from the fish tank to the grow bed.

  • The bell siphon (or a timer-controlled pump) will drain water back into the fish tank.

  • Ensure proper water flow to keep the system balanced.

• Add Fish & Plants

  • Start with hardy fish like goldfish or tilapia.

  • Choose beginner-friendly plants like lettuce, basil, or strawberries.

• Monitor the system and make adjustments as needed.

Watch this to see how I build an aquaponics system with second hand materials for FREE

Beginner Tips for Success

• Start small – Learn the basics before upgrading to a larger system.

• Test water regularly – Check pH, ammonia, and nitrate levels.

• Feed fish properly – Overfeeding leads to water quality issues.

• Choose the right fish – Hardy species are best for beginners.

What Can You Grow in a Bathtub or Barrel System?

• Leafy greens – Lettuce, spinach, kale

• Herbs – Basil, mint, parsley, coriander

• Fruiting plants – Strawberries, cherry tomatoes, peppers

• Small root vegetables – Radishes, green onions

Final Thoughts: Build Your Own Easy Aquaponics System

A bathtub or barrel aquaponics system is an affordable, space-saving, and sustainable way to grow fresh food at home. Whether you’re a beginner or just looking for a simple DIY project, repurposing materials can make aquaponics more accessible than ever!

Check out My YouTube Channel 'Candy The Aquaponics Lady'

Aquaponics is an ecosystem, and with anything it takes time to learn how it works. So, sit back and binge watch my 'how to' playlist and the 'Water Quality Made Simple' Playlist, and learn the next steps in your aquaponics system as you create the ecosystem.

Here are the next 2 videos I recommend you watching to create your ecosystem ~ before you add any fish

How Aquaponics Works as an Ecosystem

Learn More About Aquaponics

Check out the COURSES page to learn how you can get started with aquaponics now. Click HERE.

Want to get your Eyes and Hands on the FREE Online Aquaponics Essentials Course?

This is a great free resource to really understand how aquaponics is a sustainable ecosystem that will grow your organic food is a productive way.

You learn how all the 'parts' make up the 'whole', and helps to give you the foundations of understanding aquaponics.

Sign up HERE

Want to help out and Feed my Fish?? (They don't drink coffee)

Candy Alexander is a dedicated aquaponics enthusiast with a wealth of formal training in aquaculture. Over the past 15 years, Candy has been deeply immersed in both commercial and backyard aquaponics, honing her skills and expertise in this sustainable farming method.

Candy's passion lies in making aquaponics accessible to everyone. With a mission to simplify aquaponics, she believes that anyone can embark on this sustainable journey.

She encourages those new to aquaponics to "kick the tires" without a significant financial investment. Her guidance focuses on helping people start their aquaponics journey with small-scale systems, ensuring a low barrier to entry for newcomers.

Candy shares practical tips, step-by-step guides, and personal stories to inspire and guide readers on their aquaponics adventure. Whether you're a seasoned farmer or a curious beginner, Candy Alexander is your go-to source for simplifying aquaponics and fostering a sustainable gardening experience.