Bog building, also called upflow filter, eco filter, wetland filter

[sherry]

Yep, not much to do when you have a bog.
Just feed the fish and enjoy.
No filter pads to clean.

May I ask how you plumb the pump? I assume it's an external pump. Where to put the pump inlet tubing or hose? Just directly in the water? If so, would fish get in?
I just realized, I have this issue as I have lots of small mosquito fish. If it's koi it would be ok.

 

[poconojoe]

May I ask how you plumb the pump? I assume it's an external pump. Where to put the pump inlet tubing or hose? Just directly in the water? If so, would fish get in?
I just realized, I have this issue as I have lots of small mosquito fish. If it's koi it would be ok.

My pump is a submersible and is located on the opposite side of the pond (from the bog).
My pump is a Tetra DHP-3600.
It has a bunch of small holes in it for the intake, so I don't think any fry would get sucked in.
If you are worried, you can always get or make one of those pump bags for your pump or get an inexpensive prefilter.

I have a string tied to it for easy retrieval and to keep it suspended about a foot off the bottom. If it sits directly on the bottom, it might take in debris that may collect down there.

I have an 1-1/2" black schedule 40 flex PVC connected to the pump's outlet.
The flex PVC lays across the bottom of the pond, then goes over the wall between the pond and bog. You can hardly see it and there's only about 6" showing where it exits the water.
All my plumbing is within the pond/bog. No water can escape the system if there's a plumbing leak.

 

[Alexisc]

I built a bog filter in May using some of the guidance here and from other forums but I’m having some blockage issues. The filter has really saved my pond this Summer but now appears to be clogged up to the point that the water just wants to burst up and out through by snorkel, even though it’s capped (I have to weight it down with bricks).

I think the main reason is that the PVC pipe is not big enough (I wouldn’t use a 1.5 or 2 inch again) and there aren’t enough or big enough holes, I used holes and no slits, and all holes are on the side or the top (none facing downwards). Because of the complex way my pipes are connected, it’s pretty much impossible to get a snake or anything else down in there to clean it, so I’ve blasted it with a hose, which helped a little but ultimately I’m going to have to deconstruct it, make some mods, and then put it all back together.

I’m posting this so others maybe don’t make the same mistakes but would happily take other advice. Note, I used a much larger than pea-gravel to sit on top of the pipe but that still hasn’t helped. When I rebuild I will probably use a layer of Scottish pebbles and may even add a plastic mesh layer for extra protection.

 

[Magicno1]

I built a bog filter in May using some of the guidance here and from other forums but I’m having some blockage issues. The filter has really saved my pond this Summer but now appears to be clogged up to the point that the water just wants to burst up and out through by snorkel, even though it’s capped (I have to weight it down with bricks).

I think the main reason is that the PVC pipe is not big enough (I wouldn’t use a 1.5 or 2 inch again) and there aren’t enough or big enough holes, I used holes and no slits, and all holes are on the side or the top (none facing downwards). Because of the complex way my pipes are connected, it’s pretty much impossible to get a snake or anything else down in there to clean it, so I’ve blasted it with a hose, which helped a little but ultimately I’m going to have to deconstruct it, make some mods, and then put it all back together.

I’m posting this so others maybe don’t make the same mistakes but would happily take other advice. Note, I used a much larger than pea-gravel to sit on top of the pipe but that still hasn’t helped. When I rebuild I will probably use a layer of Scottish pebbles and may even add a plastic mesh layer for extra protection.


I use a wet vacuum to suck out any crud down in the updated that stops it from blocking. If you have a lot of crud it may be worth adding some mechanical filtration but not pre bog!

View attachment 153573
View attachment 153574

 

[Alexisc]

Hi Magic

I have used my pond vac too but I actually think it might have made it worse (sucking things towards the pipe vs only things already in it?)

I followed addy’s advice on filtration and I split the pump output between my Laguna pressure flow UV and the bog, the UV outlet pipe is buried in the top of my gravel and spits out at the top of my waterfall so I get the full pressure for the falls. However, I noticed at the weekend that my UV light was off and was unsure how long that’s been the case, so this has possibly exacerbated the bog issue. Bulb was only replaced in May, so shouldn’t have failed so soon. I switched out for my spare filter (Laguna PF 5000) on Sunday and just waiting for a new UV bulb to be delivered.

I am going to build an additional wetland in the autumn/winter. I have to reline the pond due to large holes and patches that keep failing, so I’m having it dig deeper and to convert the end section here into a lower level bog (my property is on a slope, downwards towards my house and terrace, so the max water level of the pond is limited by that and I’d like ti change that.

 

[GBBUDD]

One cut in the pvc is equal to at least 20 of your tiny holes. I learned a lesson years ago in the aquarium trade that those holes are way to small . Algae alone can grow and plug those up very quickly.

The second observation for anyone looking at this design would be that there are no holes in the elbows or the start of the bog area this will limit an already smallish design. By not disbursing uniformly across the entire bog.

The clean out cap needs to be a threaded end cap not just push on the pressure alone, be it air or water will force it off.

As was also mentioned the pump maybe too strong for the design splitting the output can solve that but. It is the small holes that are the problem here the reason why most advocate the cuts and face down is to prevent stone from getting into the cuts and try to block them. The slits are almost impossible to block. But i do recomend a FULL 1/8" cut or more a doble or tripple pass. With the saw blade.

One pass with a thin kerf circular saw blade is to small imo You said you used a larger stone at the pipes which is great but again the small holes will clog from what gets by the pump it self

 

[poconojoe]

I built a bog filter in May using some of the guidance here and from other forums but I’m having some blockage issues. The filter has really saved my pond this Summer but now appears to be clogged up to the point that the water just wants to burst up and out through by snorkel, even though it’s capped (I have to weight it down with bricks).

I think the main reason is that the PVC pipe is not big enough (I wouldn’t use a 1.5 or 2 inch again) and there aren’t enough or big enough holes, I used holes and no slits, and all holes are on the side or the top (none facing downwards). Because of the complex way my pipes are connected, it’s pretty much impossible to get a snake or anything else down in there to clean it, so I’ve blasted it with a hose, which helped a little but ultimately I’m going to have to deconstruct it, make some mods, and then put it all back together.

I’m posting this so others maybe don’t make the same mistakes but would happily take other advice. Note, I used a much larger than pea-gravel to sit on top of the pipe but that still hasn’t helped. When I rebuild I will probably use a layer of Scottish pebbles and may even add a plastic mesh layer for extra protection.

View attachment 153573
View attachment 153574

Where is your pump?
If it's a submersible pump, don't let it pull from the direct bottom where solid debris may collect. Position it a foot or so above the bottom. I have a thin rope tied to mine to hold it above the bottom.

 

[Alexisc]

Where is your pump?
If it's a submersible pump, don't let it pull from the direct bottom where solid debris may collect. Position it a foot or so above the bottom. I have a thin rope tied to mine to hold it above the bottom.

It sits on a brick on the bottom, so not right at the very bottom

 

[Alexisc]

One cut in the pvc is equal to at least 20 of your tiny holes. I learned a lesson years ago in the aquarium trade that those holes are way to small . Algae alone can grow and plug those up very quickly.

The second observation for anyone looking at this design would be that there are no holes in the elbows or the start of the bog area this will limit an already smallish design. By not disbursing uniformly across the entire bog.

The clean out cap needs to be a threaded end cap not just push on the pressure alone, be it air or water will force it off.

As was also mentioned the pump maybe too strong for the design splitting the output can solve that but. It is the small holes that are the problem here the reason why most advocate the cuts and face down is to prevent stone from getting into the cuts and try to block them. The slits are almost impossible to block. But i do recomend a FULL 1/8" cut or more a doble or tripple pass. With the saw blade.

One pass with a thin kerf circular saw blade is to small imo You said you used a larger stone at the pipes which is great but again the small holes will clog from what gets by the pump it self

Thank you for this advice. I had someone do this for me and he said he knew better when I told him to do slits. The end cap is threaded but it’s almost impossible to get tight enough because the snorkel doesn’t stick far enough out of the gravel to get enough grip. Lots of things learned from this build.

 

[addy1]

My pipes have slits, facing down, used a saw to make them. 1/4 inch or so plus minus in size. I draw only "clean" water, ie no debris. I also use a external pump with a leaf basket in front of it. I only clean the leaf basket when I shut down the pond in the fall for the winter. Minimal big debris is drawn into the leaf basket, none makes it to the bog. My pipes have never plugged up (11 years or so now)

Keep in touch during your rebuild, we will love to help as much as we can.

 

[Alexisc]

My pipes have slits, facing down, used a saw to make them. 1/4 inch or so plus minus in size. I draw only "clean" water, ie no debris. I also use a external pump with a leaf basket in front of it. I only clean the leaf basket when I shut down the pond in the fall for the winter. Minimal big debris is drawn into the leaf basket, none makes it to the bog. My pipes have never plugged up (11 years or so now)

Keep in touch during your rebuild, we will love to help as much as we can.

Thank you I am also planning a second and much larger bog because I need to have my pond re-lined anyway. Haven’t quite figured out how to execute it yet - see image for the section of my pond I’d like to steal for the bog - I want it to have a lower water level vs the pond because it’s naturally at a lower point of the property and adjacent to a terrace, and currently limits the max fill height of my pond. I’ll post about this in a couple of weeks once I’ve done a bit more of my own research.

Would love to have a skimmer added to house the pump too.

 

[poconojoe]

Thank you for this advice. I had someone do this for me and he said he knew better when I told him to do slits. The end cap is threaded but it’s almost impossible to get tight enough because the snorkel doesn’t stick far enough out of the gravel to get enough grip. Lots of things learned from this build.

That pipe sticking up is not a snorkel, it's a clean-out stack.
A snorkel is a pipe with a diameter big enough to drop a pump down into.
The snorkel and centipede setup is different where as there's a void that is pitched so any debris will settle in the bottom which then can be sucked out by dropping a pump down there. This type of bog is mostly used for large ponds.

 

[addy1]

Nice looking pond!

Just make sure your bog walls are higher than you think they need to be, at least 5 inches over the top of the gravel.

 

[Alexisc]

That pipe sticking up is not a snorkel, it's a clean-out stack.
A snorkel is a pipe with a diameter big enough to drop a pump down into.
The snorkel and centipede setup is different where as there's a void that is pitched so any debris will settle in the bottom which then can be sucked out by dropping a pump down there. This type of bog is mostly used for large ponds.

hm this sounds like semantics but please correct me if I’m missing some pond lingo I need to be aware of for discussions here. Aquascape didn’t invent the term snorkel and even so, isn’t it still cleaning access? Why would the term be different based on the diameter of the cleaning tube?

 

[Mmathis]

I cut slits in my bog instead of drilling holes. Also, I oriented the pipe so the slits faced downward. My thinking for the latter is that it would be harder for debris to block the slits.