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How to use fish to grow the best indoor plants

I love plants and I love fish tanks. Both plants and fish tanks add life and light into any space big or small. So the questions I asked is how to use fish to grow the best plants?

How to use fish to grow the best indoor plants Direct plant

Aquaponics is the answer.

Aquaponics is fun and easy. What is aquaponic? It is the art and science of using fish “poop” water to feed your plants an great level of nutrients.

Here is the basics behind the science.

How to use fish to grow the best indoor plants

But you don’t need to be a scientist to make it work!

The fish naturally produce just what the plants need. And the plants naturally clean the water making the fish happy.

The fish will grow the best indoor plants you have ever had without much help from you.

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All you need to do is feed your fish and they will do the work. There is no better fertilizer than fish poop.

There are a few things you need to decide when starting your aquaponic garden.

  • How big is the fish tank you want to use
  • What kind of fish do you want have
  • What kind of plants do you want to grow

The great thing is aquaponic will work for almost anything.

Lets look at your choices closer.

How big should your fish tank be?

Direct plant in a fish tank

How to use fish to grow the best indoor plantsAquaponics

You can grow one plant in a 5 gallon tank. A small tank is best for a direct planting situation.

If you are looking to grow 3 or 4 plants a 10 gallon tank is perfect for direct planting.

But wait!

What’s “direct planting”? Direct planting is just what it sound like. It is when you put your plant’s roots directly into the fish tank. Simply take a plant and put it into a net cup. Then hang the plant in the net cup directly into the fish tank.

Important to remember when directly planting over a fish tank.

  • Keep the standard filter, if any, with the original tank set up.
  • Air stones should also stay in the tank as normal.
  • Heater, if any, should stay in the tank.
  • The fish may nibble on the roots however this will not harm the plant.
How to use fish to grow the best indoor plants Mollies

Using a 20 gallon or bigger tank to use fish to grow the best plants.

You can do great indoor gardens using fish tanks that are 20 gallons and bigger. The best and most effective way to grow plant with a larger tank is to use a NFT system.

NFT basics.

Nutrient film systems or NFT is simply means a system that moves the water from a tank into a river that flows past the roots and back into the tank.

How to use fish to grow the best indoor plants NFS systems

This type of system is perfect for any large fish tank. Commercial aquaponics farms use NFT systems.

Do be intimidated!

These systems are super easy to set up and super flexible too. They can be made to fit any space. And best of all you can make these from things you can find at any home improvement store.

Here are two systems that I have running, one made with gutters and one made with sheet plastic, both inside a wood frame.

How to use fish to grow the best indoor plants Kitchen Aquaponics
How to use fish to grow the best indoor plants Window Aquaponics

Important things to remember when using fish to grow the best plants in a NFT system.

  • You can grow an average of one plant per gallon of water in the fish tank
  • Don’t run the filter. Remove the standard filter and use an exterior filter.
  • No need for the air stone.

Please read DIY Aquaponic filters to find out more details about filtering.

What kind of fish grow the best indoor plants?

Beta fish and mollies are standard in many home tanks. These fish work great for the smaller direct planting systems. Give you fish a home in the right environment regardless of your plants in a direct plant system.

Pay attention to your plants. If they look healthy than the system is working fine.

Larger systems will do better with high nitrogen producing fish like gold fish. I have 7 gold fish feeding 30 plants. The same 30 plants would need 10 or 11 mollies.

How to use fish to grow the best indoor plants Gold fish

What kind of plants can grow with fish?

Really any kind of plants.

I am an avid indoor vegetable gardener. I have grown lettuce, cucumbers, tomatoes, broccoli, spinach, even squash.

Please check out my new book!

House plants grow great with fish. Almost any house plant can benefit from the nutrients from fish poop.

Part of the fun is experimenting with different plants and fish.

There are additional benefits of the aquaponics to the environment.

If you have an interest in learning more about aquaponics in CSA and other commercial industries check out this article from volcano veggies

You should give Aquaponics a try! Learn how to use fish to grow the best plants indoors. You may never go back to soil again.

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This Post Has 4 Comments

  1. This is cruel to those goldfish. Goldfish can grow over a 1′ long and require 20 gallons minimum for one so the ammonia doesn’t harm them. You have two in less than half the size tank you’d need for one

    1. Thanks for pointing that out! Yes that is true. You need to adjust you fish and tanks to be both healthy for the plants and fish. I start young fish out in small tanks. As each fish grow I put them a bigger tank. I hate to see those tiny fish bowls planters mounted on the wall. Fish need room! Thanks again for your comments

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