How To: Bog Filter

HOW TO: Build a Bog Filter

Bog filtration is one of the best filtration systems for your pond.  It requires some extra space, but it also provides a very high level of filtration with minimal maintenance.  It is all natural and can be made to look as though it was created by Mother Nature within your pond’s surroundings. 

Here is a step by step with pictures from our bog filtration we installed in one of our Koi Ponds.

1. The first step is to calculate the size of your bog.  We recommend you size as much as 30% of your pond’s surface area into your Bog.  For instance, if you have a 10X10 pond (100 square feet,) you would build a 30 square foot bog.

Step 1 | Water Garden Gems

2. The bog should be 12” deep, and make sure you plan the elevation properly to get the spillway you are looking for.

3. Build your walls, making sure you focus on making a LEVEL bog garden.  If you use a liner for your bog, also take into account that the liner will need protection, so lay underlayment or felt/carpet, down first to protect it.

Step 3 | Water Garden Gems

4. Lay in your liner and then fill it with water and plumb your Bog.  The plumbing is key.  You need to use slit PVC pipe and lay it across the bottom of your bog so the water is dispersed evenly throughout your gravel bed.

 bog 8bog 9

5. Fill in your bog with 3/8” peat gravel.  Be sure it is prewashed or wash it yourself beforehand to decrease the amount of dust you are introducing into your pond.  Take caution when filling with your gravel that you do not break or shift your underlying pipe.

bog 4

6. Turn on your pump and test your elevations and set up.  You should have 1-2 inches of water moving above your gravel bed.  Now you are ready for plants. 

bog 3

Choose plants wisely.  There are many many different types of Bog plants and they come in all heights, colors, growth rates, etc.  Choose a variety, but do your research as to how invasive some are as you do not want then to take over.  Your plants can be planted into your bog in pots as shown, but it is recommended that you take your plants out of the pots and let them root into the gravel and expand.  The more roots you have in your bog, the more filtration you will achieve.

bog 2bog 1 

Annual maintenance will be to trim your plants and make sure they are not overgrowing their space.  You will ocassionally need to thin out your plants and clean your gravel. This could be every other year or it could be every 5 years, depending on how large your bog is in relationship to your pond and water quality.  This is by far one of the lowest maintenance filtration systems you can put on your pond and is all natural.


***Feel free to call or come by for more details, expertise or to shop our vast array of over 50 different bog plants for your new filter system***


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