Adding a bog filter to raised pond.

[Shell-Fish]

Hey all,

Been seriously reading about bog filters and how some members here have been using this filtration method to their ponds and the success stories from it. I wished I'd looked in to bog filters as only after reading, didn't even realise how efficient they can be.

My dilemma is..

Could I add a bog filter to my existing raised pond?
What height should it be?
What should it be made out of?
Do you need to fill with soil or rounded small stones?


Here's a pic of my setup and I can easily T off water from the pond pump to feed the bog but looking in to advice before plunging in.

This is possible layout of the shape of the bog filter as well as position. I could also place on opposite side (top left of pic) but need advice.

I do also have a water fall section from the Eazypod filter (top middle of pic) but not very deep - about 15cm depth but not easy to get to also.

Any advice would be appreciated.

 

[IPA]

could you use something like this?

 

[Shell-Fish]

View attachment 130434
could you use something like this?

Good find
Does it have to be a certain ratio to the pond water volume or stock?
I'd like to look more aesthetic as possible.

 

[IPA]

It needs to be deep enough for the manifold, layer of gravel, and a couple of inches above the water level to prevent overflowing the sides. Generally 18” of pea gravel and that’s just because you don’t want the roots growing into the manifold but if you can only accommodate 12” just choose less aggressive plants. Any container will work or you can make your own and rock wall the outside. If you did you could make it any basic shape, triangular running along the back wall some. 20 to 30% is ideal but any bog is going to be a benefit, just maybe not enough not be dependent on additional filtration.

 

[Shell-Fish]

It needs to be deep enough for the manifold, layer of gravel, and a couple of inches above the water level to prevent overflowing the sides. Generally 18” of pea gravel and that’s just because you don’t want the roots growing into the manifold but if you can only accommodate 12” just choose less aggressive plants. Any container will work or you can make your own and rock wall the outside. If you did you could make it any basic shape, triangular running along the back wall some. 20 to 30% is ideal but any bog is going to be a benefit, just maybe not enough not be dependent on additional filtration.

Thanks IPA.
My new filter is doing a bang up job but I'm in need of more marginal pond plants and a bog seems to be the only way. I'll look around and see what i can find.

Thanks again.

 

[IPA]

Thanks IPA.
My new filter is doing a bang up job but I'm in need of more marginal pond plants and a bog seems to be the only way. I'll look around and see what i can find.

Thanks again.

I’ve purchased all kinds of containers trying to build small bogs before my final build, from trash cans cutting off just the bottoms, recycle bins to preformed pond liners. You’ll never look at a plastic container the same again, haha.

 

[Shell-Fish]

I wonder if I can "feng-shui" my plastic bog filter somehow. Going to be interesting.

What type of flow do you have on your bog? thinking would faster be better since the pond pump will be almost below the corner where bog will be.

 

[IPA]

Can you post some more pictures. The back left side, from photo, looks interesting. Where the water is pumped up into a shallow pool and then waterfalls back into the pond? Looks like you could add a lot of free root plants there. In the lower right where you marked just add a tee and valve to split the flow a little, raise what looks like a divide in the pond, and overload that with free root plants and a short pvc manifold cover with just enough gravel to hide it. The pea gravel is really the substrate that the plant roots grow in but the plants, and plant roots, are really doing the heavy lifting. The bog also allows the proper placement, height, of plants which is hard to accomplish free rooted so maybe just a very large plant basket could work if you can get to flow from bottom to top, not just bypassing the roots as water will always flow where there is least resistance.

 

[addy1]

Any container that fits your area will work. The bigger it is the stronger the sides need to be to hold the water and gravel.

I made a mini bog for my hot tub pond, a long flower pot, water fed via a tub stuck in the bottom (made a hole) it goes up through the media (this one is kitty litter) and small water fall back into the pond. It is working great for that pond.

I have very slow flow into the mini bog therefore the kitty litter. It is full of water willow. Which is blooming beautifully

 

[Shell-Fish]

Can you post some more pictures. The back left side, from photo, looks interesting. Where the water is pumped up into a shallow pool and then waterfalls back into the pond? Looks like you could add a lot of free root plants there. In the lower right where you marked just add a tee and valve to split the flow a little, raise what looks like a divide in the pond, and overload that with free root plants and a short pvc manifold cover with just enough gravel to hide it. The pea gravel is really the substrate that the plant roots grow in but the plants, and plant roots, are really doing the heavy lifting. The bog also allows the proper placement, height, of plants which is hard to accomplish free rooted so maybe just a very large plant basket could work if you can get to flow from bottom to top, not just bypassing the roots as water will always flow where there is least resistance.

Here a couple of pics from different angle.

 

[poconojoe]

Looking at your last picture, that area to the left where the three pots are sitting. How deep is that? You need about 12" of pea gravel. If it's deep enough, you can lay your distribution manifold in there then cover it with pea gravel. You already have the base built and a liner installed. Boom! Instant bog!

 

[poconojoe]

Oh, to answer your question... the bog should only have pea gravel. No soil.

 

[Shell-Fish]

Hey all, can you please let me know if this would be suitable to sit on top of my pond, just like in diagram and be used as a bog filter?

Plan is to drill a hole in rear (just above where it says 90L) and and drill another hole just a few cm from top (where it has 73cm)
The whole on top will be used to attach a pipe drain for returning back to pond.

Location of container.

What I do need to know before ordering is following.

What size hard pipe to use for the inside?
Can I use any flexi pipe for T off from main pipe/pump?
For this size container, what media would be ideal for best filtration?
Looking at my pond (4200 litres) would this container be too small for sole filtration? current filtration is a Eazypod.


Thanks.

 

[poconojoe]

I would stick to using ridgid PVC pipe in the bottom of the bog. It's cheap, easy to work with and definitely will never crush. I'd be afraid of any corrugated pipe getting crushed.

I always suggest using bulkhead fittings to make the transition between the outside pipes and the pipes inside the bog. Bulkhead fittings are inexpensive and give you a positive seal without using any glues or adhesives. They come in any size you need to match the size of your pipes/hoses. They also come in a few varieties for different types of connections, double threaded (threads on the inside and the outside), threads on one side and slip on the other and slip on both sides. Slip means it's a female in which you glue your pipe to it.

What size to use inside your bog, the bigger the better in my opinion. For your size bog container maybe 1 inch or 1-1/2 inch, if you can. If your pump has a smaller size for it's output, you can get a reducing bushing to make the larger bog pipe connect to the smaller pump pipe. My bog pipes are 2", but my bog is much larger, somewhere around 12 feet by 5 feet. My pump has an 1-1/2" outlet. I increased it to 2".

 

[Shell-Fish]

Thanks @poconojoe
Should i go for layers of mixed media or stick with one only?