The Key Facts In Understanding A Bog Filter Diagram

Last Updated on December 7, 2021 by Marco C.

A bog filter is a unique way to clean your fish tank while producing more plants!  This article will go over a bog filter diagram and teach you how to make your own bog filter at home.

But, what exactly is a Bog Filter?  A bog filter is a low-cost, low-maintenance filtration system which uses the principles of nature to clean your water.  Not only is it easy to install, but it also looks very aesthetically pleasing.  

In fact, if built right you will want to show off your bog filter to all passersby.  Does it sound too good to be true?  Read on to look at a bog filter diagram and learn how to make this great idea a reality for your aquaponics system.

What Is A Bog Filter?

The most basic definition of a bog filter is that it is a separate container which has many water-loving plants in it.  It gets the name “bog” because it uses plants that would be commonly found in swampy areas.  

These plants have a unique ability to filter and clean water.  In fact, this is why wetlands are so valuable for our planet. 

 We need plants and wetlands to preserve our water systems and keep them clean.  The bog filter mimics the natural world to keep your tank water clean.

Every aquaponics fish tank needs to have a filter. According to the Southern Regional Aquaculture Center, “All cultured organisms, vertebrates or invertebrates, finfish or shellfish, produce waste as a result of the nutrition they receive.”  

This is why a filter is crucial in keeping your ecosystem balanced and thriving.  If you are a sustainability person, consider using a bog filter system rather than a store-bought filter.  

Think of your bog filter as a supplementary pond that sits next to your tank.  It is much smaller than your tank.  Usually, it should be about 1- Tenth or 2 Tenths of the size of your tank. 

If your tank is 150 gallons, your bog filter pond would be between 15-30 gallons.  Water is pumped out of your main tank, into the bog filter then back into the tank once it’s been clean.  

should be about 1- Tenth or 2 Tenths of the size of your tank

This is one of the most natural ways to filter your tank.  I also like it because it adds more plants to the world.  Plants are important in absorbing carbon and keeping our beautiful earth thriving! 

The roots from the plants trap, store, and use excess pollutants from your main tank.  They trap things like excess nitrate, ammonia, phosphate, and other organic debris. The result is nice, clean water for your fish to enjoy!

Parts Of Bog Filter Construction

Bog filters are relatively easy to construct.  You need to pump the water from your fish tank directly to the roots of the plants.  So you will have to create piping which is located underneath the plants.

Fill the filter container with a layer of pea gravel.  This will help filter the water and also give the roots something to latch into.  

Be sure not to make your gravel layer too thick.  On average, you do not want to make this laid more than 12 inches thick.  

It is very important that you use ⅜ inch diameter pea gravel.  If you use anything larger, this will compromise the effectiveness of your filter.  When you use a smaller diameter, it will easily clog your piping system.

The plants sit directly in the gravel and water.  It is basically using hydroponic principles to grow. 

You can buy PVC pipes from the store and drill small holes to disperse the water through the roots. Make sure to not drill your holes too large.  They need to be slightly smaller than the gravel to ensure that the gravel does not fall into the holes.  

Look at a Bog Filter Diagram to know exactly how to make it.

Often these filters are raised above your main pond.  In this method, you are utilizing gravity to send the water back into your tank.    When you construct your bog filter, use a pond liner or another impermeable structure to hold the water.  

Once you build the structure, pump, and piping system you need to move on to your plants.


Understanding Bog Filter Plants

When planting your system out, keep in mind that your plants will spread and grow over time.  This is why you should not start out with too many plants.  A general rule of thumb is to plant one plant per square foot.

So, if your filter is 10 square feet, use 10 plants.    You also have to be sure to use the correct bog filter plants for your region. 

Certain plants will grow too fast resulting in the roots growing down into your pipe holes causing serious blockages.  If you notice something like this happening, make sure you thin out the plants or switch to different ones that grow slower.

When choosing your plants to be sure to consider which types of plants you like to look at.  Your bog filter will be very visible.  Some nice plants to use are Gunnera, Thalia, ribbon grass, hostas, and many more.

Check your local wetlands to see which plants grow well there.   In fact, you can even take some of those plants directly from the wetland to transplant into your bog filter.

Building a bog filter is very similar to building an actual pond.  Approach it in the same way but make sure you have the right pumps and pipes set up to move the water where you need it to go.  If you have time to make this system, it is highly recommended because it will last a very long time and requires very little maintenance.

Before you build the system, make a bog filter diagram to ensure the design has no gaps.  If you want to make a bog filter, make sure you plan ahead and create your main tank system with this in mind.  We encourage you to be brave and take this challenge!

Feel free to comment and ask questions below. 

Read more about: Your Perfect Guide To Aquaponics Filtering Systems