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

[stevekind]

Has anybody planted "ransoms" (wild garlic / Allium Ursinum ) in their bog filter? It grew all around the boggt edge of our old pond and it's so pretty in early summer (and you can eat it) - I popped a couple into the bog filter last week and it's looking really happy - just a bit worried it will try to take over!

 

[addy1]

I have not tried it, everything grows well in a bog if it likes the wet and does take over, Mine is a "wild" bog if it grows it gets to grow and gets over grown. Occasionally I go in and groom some of the plants.

 

[poconojoe]

Wow! So much to read!
I have some questions and ideas...

It seems to be the consensus here that the slits on the manifold pipe should be facing down. Most of the articles elsewhere online say they should be facing up. Now I tend to trust everyone here and will probably go that route. But just wondering why the different views? I'm thinking facing down the gravel will less likely tend to clog the slits. Is that the main reason?

Another thought on the manifold construction:
I see everyone using tee fittings creating branches to get full coverage. I was thinking of just having one continuous pipe turning back and forth (two 90 bends at each end) so that I know there will be even distribution of the water. Any thoughts or concerns on this idea?
Should the manifold be level? Or would that matter at all since there will be considerable force from the pump anyway?

And a question about the liner:
Do I pitch (the bottom) of the liner toward the pond? Or have it level and just rely on the lower wall section for the water to flow out?

 

[poconojoe]

Sorry...another question...I might be over thinking this stuff!
I was thinking of keeping most of my manifold piping toward the side of the bog opposite of the pond. Thinking that if it was too close to the pond, the water would be only flowing through a limited amount of gravel. I think I would want the water to seep through as much gravel as possible.
Am I over thinking? Getting too technical?

 

[addy1]

I'm thinking facing down the gravel will less likely tend to clog the slits. Is that the main reason?

I put mine down to keep the pea gravel from clogging the slits, that was how I thought it out. Also put a extra piece of liner under the pipes to keep the water from pounding constantly on the real liner.

I see everyone using tee fittings creating branches to get full coverage.

mine is just two 26 foot lines of 2 inch pvc pipe joined by a T near the input from the pump.

Do I pitch (the bottom) of the liner toward the pond? Or have it level and just rely on the lower wall section for the water to flow out?

Mine is flat water flows out over the water fall

I was thinking of keeping most of my manifold piping toward the side of the bog opposite of the pond.

I have a line running down the far side of the bog and one running down the near side. It does not seem to matter.

 

[poconojoe]

Addy, I guess I'm over thinking things!
Uh, technology question...
How or what did you use to draw that quick blue pipe drawing in the previous post?

 

[addy1]

How or what did you use to draw that quick blue pipe drawing in the previous post?

I use a app on my lap top, called snipping tool. You can grab a picture and draw on it so I just grabbed a white square and drew some quick lines. It is part of windows.

I have the note 9 I could have done it with pen on the phone. But I don't post well on the phone.

My hands give me a lot of issues if I try to use the smaller phone. I tend to use the lappy more than anything.

 

[MajorDan]

How do you know how much water to send through the bog? My pump delivers 3000gph. I have roughly half of it going through the bog. The rest goes to my waterfall box filter with bio balls and red luikia on top and a small amount goes unfiltered into my small upper pond that has plants in it. I have valves everywhere so I can alter the amount going to each place. I guess my question is, can you have a high flow rate through the bog or should it be a slow flow?

 

[Lisak1]

Slower is better. But his slow? No clue.

 

[stevekind]

How do you know how much water to send through the bog? My pump delivers 3000gph. I have roughly half of it going through the bog. The rest goes to my waterfall box filter with bio balls and red luikia on top and a small amount goes unfiltered into my small upper pond that has plants in it. I have valves everywhere so I can alter the amount going to each place. I guess my question is, can you have a high flow rate through the bog or should it be a slow flow?

The advice I have been given and read at various places on the interenet is that all the water in your pond should pass through the bog filter in one to two hours. Bear in mind that lifting the water and diverting it through valves may very well result in a pump output of less than the rated level. I reckon mine takes a bit longer than two hours and the plants are doing fine. Stands to reason that the slower the water passes through the gravel, the more nutrients will be taken up by the plants. Hope that helps.

 

[MajorDan]

Well I just tuned my bog flow down a notch. Maybe I had it flowing to fast.

 

[addy1]

I pump a lot of water through mine but it is pretty big.

 

[Lisak1]

all the water in your pond should pass through the bog filter in one to two hours.

That's a big variable - I mean two hours is double one hour and one hour is half of two hours. So that's not really a formula at all. That's why my answer is always "slow is better. But how slow is slow?" It makes sense that you don't want the water forced through the bog at a high rate of speed and I'm sure some genius somewhere has a formula that takes all factors into consideration (how much gravel? How many plants? Bog size? How deep? How wide?Pond size? How many fish? Temperature? etc etc etc.) but for the average homeowner I think observation is your best tool. (Especially if, like me, you just don't do math. Please see my explanation above of how two is half of one.)

We set our water flow so we can just see the surface of the bog moving if you look real close. (We have a couple of inches of water above the gravel. The frogs have told us they prefer it that way. We live to make them happy! haha!) And my biggest observation as always is the pond - the water looks good, smells good, the plants are thriving, the fish are healthy - all is well.

@stevekind if you could share some of those internet sources on bog flow, I would love to read them. We searched relentlessly when we were building our bog and ended up just making a good guess. We have a secondary waterfall that we can send water to so we adjust accordingly, but it's really not based on anything but the observations I mentioned above.

 

[addy1]

We set our water flow so we can just see the surface of the bog moving if you look real close.

I can see mine running like a stream.

 

[Timothy]

Bog water flow........
Although our bog was as much a "make-work" project to keep an old man busy and off the streets, it is functional as evidenced by the sludge left behind once the water passes through it. It is a little smaller than conventional proportions dictate, but is still effective and adds a dimension to the setting.
The water flow is relatively slow as can be seen in the photo, but given the amount of water in the spillway, the volume is modest. We also didn't strive for a formulated amount of water, just what seemed to work, which can cover a wide spectrum from our meandering to Addy1's robust flow.

Our bog is just an above ground box with a liner, pea gravel, and pump.


The overflow spills into a sluice that returns to the pond under the "dock". This has an "inspection" box on the return end.



The apparent holes in the surface are caused by the water coming up through the gravel where the debris falls out creating the sludge mat that feeds the plants and harbors tads. The streaks in the image are actually reflections of adjacent plants giving an indication of how sedate the flow is. By mid summer this will all be naturally covered with plants. (I had to do a major culling last fall.) Although the water flow is relatively slow, it is a decent volume and too much for mosquitoes.