How does a bog work?

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Hello all, pond newbie here.

I have what amounts to a large birdbath with a waterfall. After one summer with it (and a few goldfish), I am interested in making it deeper, probably no deeper than 24" due to local zoning rules.

I've read about people putting in bogs as part of the water filtration system. I tried to search on the word "bog", but got a message that "bog" is not a searchable term. (?)

Anyway, I'm interested in understanding how a bog works, how it's hooked up to the pond, and probably a bunch of other things I don't know yet that I don't know.

Could someone please give me a basic explanation of how a bog works?

Thanks!
 
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Thanks, Addy. Do you mind that I still have a few questions? Remember, I'm a beginner, and I've never seen one of these in action.

1. Is the concept to pump pond water into the bog? How do you get it from the pond to the bog? (Just confirming...your post doesn't actually say what the bog pipe is connected to.) (Or at least I didn't see it.)

2. Do you draw from the bottom of the pond? Is there a recommended flow rate? It would seem to be relatively slow, given the small spout you have from your bog to the pond. Do you actually pump water back into the pond, or does it just overflow from the bog? Does it overflow from more than that one spot?

3. What role does the relative elevation of the bog to the pond play? The spot I'm considering is slightly uphill from my pond. Does this matter?

4. Is it possible/recommended to pump bog water to a waterfall back into the pond?

5. Do you still run pond water through a filter or skimmer? (in our case it goes from the skimmer to the waterfall.)

6. Does this take the place of a biological filter? We have one of those bags with a videotape-like medium in our waterfall.

Sorry if I'm being obtuse. I'll need to know all these answers (and more!) if I am to convince DH that this is a good idea.

Thanks for your help!
 

addy1

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koshki said:
Thanks, Addy. Do you mind that I still have a few questions? Remember, I'm a beginner, and I've never seen one of these in action.

1. Is the concept to pump pond water into the bog? How do you get it from the pond to the bog? (Just confirming...your post doesn't actually say what the bog pipe is connected to.) (Or at least I didn't see it.)
I use an external pump, the water is pumped into the bottom of the bog, upflows through the gravel. Slits cut into pvc piping.
koshki said:
2. Do you draw from the bottom of the pond? Is there a recommended flow rate? It would seem to be relatively slow, given the small spout you have from your bog to the pond. Do you actually pump water back into the pond, or does it just overflow from the bog? Does it overflow from more than that one spot?
I draw from around 1 foot up from the bottom of the pond, my pump is rated at 6800 or so gph. My bog flows back into the pond via a 3 foot wide water fall rock, it also comes over the wall here and there.

koshki said:
3. What role does the relative elevation of the bog to the pond play? The spot I'm considering is slightly uphill from my pond. Does this matter?
You can have it as high as you wish, mine is around a foot or higher than the pond water surface. My bog is on the down slope side of the pond, had to build a 8-10 foot berm wall to support it.

koshki said:
4. Is it possible/recommended to pump bog water to a waterfall back into the pond?
With a bog you don't really pump the water out, it just flows out, mine flows out via a water fall rock. Make the bog higher than the pond, waterfall back into it. This is early spring, heron net in place, plants just starting to grow.
The skimmer is at the far end of the pond, the line coming from the bottom of the pond is 3 inch pvc
DSC05412.JPG

koshki said:
5. Do you still run pond water through a filter or skimmer? (in our case it goes from the skimmer to the waterfall.)
I have a pool skimmer with a leaf basket to collect large stuff and a leaf basket in front of the pump to collect anything that gets pumped up from the pond line.
koshki said:
6. Does this take the place of a biological filter? We have one of those bags with a videotape-like medium in our waterfall.
I have no other filtration in my pond except the bog. The shunbunkin tank has a 55 gallon sort of skippy type filter, mainly because the water going into that tank was unfiltered big pond water.

koshki said:
Sorry if I'm being obtuse. I'll need to know all these answers (and more!) if I am to convince DH that this is a good idea.

Thanks for your help!
anytime!
 
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Real simple explanation... You pump the water from the pond into the bottom of the bog. The water flows up through all the rocks. The debris gets trapped in the rocks and roots and the plant roots use it for nutrients. Clean water overflows the bog and usually just waterfalls back into the pond.
So yes generally the bog is a bit higher than the pond so the water gravity falls back to the pond.
Obviously it is important the the overflow section of the bog be over the pond, so all the water returns to the pond.
 
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Thanks to you both for such great information. I'm starting to get it now!

If I get to remodel my pond next summer, I calculated it would still only be about 500-550 gallons. If I wanted water to flow over the waterfall, and also flow in from the bog, would I need a separate pump? Is this even feasible with such a small volume of water? Does it defeat the purpose of the bog to have part of the water pumped over the falls instead of into the bog?

I really like the idea of putting a lot of irises in a bog. I've already got some Japanese iris planted in that area, and think a bog filled with them would make a nice backdrop to the pond.

Oh, and I can't find this answer...what's a "skippy"?
 
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In theory, you only need one pump, depending on its flow rate. You could take your line coming from the pump and split it into two lines with a "t" splitter and then run the lines wherever you want.
 
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Hi Koshki

I have pumps about a foot off the bottom of the pond (in case something goes wrong they wont drain the pond entirely), they have hoses that run to my skippy filters and my skippy filters overflow into a small bog then the water comes down a waterfall back into the pond.

Here is a pic taken in March when I turned the pond back on this year. You can see the two skippy filters well and how they overflow into the small bog. I have two pumps, but one had too much water flow for the skippy so I split the hose and put one going directly to the bog.

DSCN3500_zps09ac5e79.jpg


Here is a picture taken last spring before things really grew in.

DSCN3581_zpsde1677d4.jpg


Here is a picture mid summer
DSCN4387_zps6a512389.jpg


Standing behind the skippies and small bog looking back at the pond
DSCN3966_zps87443983.jpg


831324_zps15822989.jpg


I believe it is better to pump the water under the gravel in the bog rather than flowing over the top like mine though. That way the moving water is channeled directly to the roots where they can clean the water. I am planning on re-doing the pond in 2014 and there will be a much larger bog with perforated PVC running under the gravel for better filtration then the bog will overflow down a similar waterfall into the pond.
 
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BTW, both Skippy filters and bog are considered biological filtration. Some of us have either or both and have not had any issues without having any other type of filtration. For the size of your next pond I suspect a small bog would keep it very nice and clean. Plus it seems like you have a green thumb and would really enjoy bog gardening. I have seen pictures of your lovely waterfall. I would use dirt the high school kids dig out next spring to build up and area behind your waterfall. It is best to use one large piece of liner to line the pond and bog in one continuous piece so there are no seems. Then run your hose to a perforated piece of pvc in the bottom of the bog, fill with gravel and plants. Make sure the lowest side of you bog lines up with you waterfall so the water runs into the bog via your pump then overflows down your waterfall and back into the pond.

When considering bog plants you don't have to buy pond plants. They are much more expensive and many normal plants you may already have in your yard will work just as well.

I have found any day lilies, iris's and hosta's grow great planted bare root into the gravel of a bog. They are easy to take starts off of as well if you already have them planted around your house.
 
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Addy and Pecan, I just love your ponds and bogs:) I think i've given up on a bog for my pond. We landscaped a stone patio on one side of the pond, plus I don't want to take up all my liner and start over.

I may do a small container type bog for the enjoyment of gardening:) Kim
 
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Pecan, the transformation of your yard is amazing! I'll bet your neighbors are happy you moved in!

I was thinking that using a preformed pond might make getting the "tip" of the bog easier. Although I suppose it would be easy enough to just lower the berm between the bog and the pond. Well, I have a few months to work that out. I guess you dig a big hole either way.

I do enjoy gardening. However, the bog is going to be out of my reach from my wheelchair, so I'll need to find some shade plants that need a minimum of care. Some deadheading is not a huge problem, as I have a telescoping pruner that extends to 10'. I'm thinking some hostas and irises. Any suggestions for hummingbird attractors in the bog?
 

addy1

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archimedes said:
I was wonder how deep the pea gravel is supposed to be. Can any one tell me?
Most bog growing plants are shallow rooted, a few inches deep. Around 12-18 inches of pea gravel is plenty. I have 2.5 feet of pea gravel (had to fill the hole I dug lol), only the rush (a type of grass) goes down deep, and they are only around 1.5 feet in length.
 
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koshki said:
Pecan, the transformation of your yard is amazing! I'll bet your neighbors are happy you moved in!

I was thinking that using a preformed pond might make getting the "tip" of the bog easier. Although I suppose it would be easy enough to just lower the berm between the bog and the pond. Well, I have a few months to work that out. I guess you dig a big hole either way.

I do enjoy gardening. However, the bog is going to be out of my reach from my wheelchair, so I'll need to find some shade plants that need a minimum of care. Some deadheading is not a huge problem, as I have a telescoping pruner that extends to 10'. I'm thinking some hostas and irises. Any suggestions for hummingbird attractors in the bog?
Thank you :)

I have a ton of hummingbird plants, but they are all low water plants, planted in full sun outside of the bog like Hyssop, Jupiters Beard, and Fire Chalice.. I have yet to find plants for my bog that flower a lot, Maybe Addy has some ideas.
 

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