Pond Renovation...Bog Plumbing ?

[Meyer Jordan]

True but wouldn't the resistance of the gravel, roots, debris cut down on that considerably. Maybe I am missing something using only a gravity system with no pump. Sounds like it will be divided to the stream and the bog, not sure on the rate of each from the drawing. I am still of the thought that this would not work ( as least not work as it would need to ) as a gravity flow only system. Am I wrong with this thinking.

It all depends on the desired end result.
True Constructed wetlands are all gravity flow, whether surface flow or subsurface flow. This, and their size and design, determine the overall filtering efficiency. Resident time (amount of time that the water takes to traverse the wetlands) is all important in achieving this efficiency. Typical minimum RT for a constructed wetlands is 5 days.
Of course, the constructs used in ponds that are referred to as 'bogs' are not quite the same thing as a true constructed wetlands, but the same biochemical laws apply.
First, one must decide exactly what the primary function of 'a bog' is to be. Is it mechanical filtration? Biological filtration? Water polishing? Or some combination of these? Each will have a different optimum flow rate.
I kind of wandered there, but the answer to your question is - Yes, gravity flow will work in a 'bog'. A separate plumbing circuit would be required, however.

 

[RobAmy]

I do have a pump I can use for the bog circuit. I don't know enough about water flow to say if the gravity flow idea would work or fail. My intention was to use the forces of nature if possible and not waste electricity

It all depends on the desired end result.
True Constructed wetlands are all gravity flow, whether surface flow or subsurface flow. This, and their size and design, determine the overall filtering efficiency. Resident time (amount of time that the water takes to traverse the wetlands) is all important in achieving this efficiency. Typical minimum RT for a constructed wetlands is 5 days.
Of course, the constructs used in ponds that are referred to as 'bogs' are not quite the same thing as a true constructed wetlands, but the same biochemical laws apply.
First, one must decide exactly what the primary function of 'a bog' is to be. Is it mechanical filtration? Biological filtration? Water polishing? Or some combination of these? Each will have a different optimum flow rate.
I kind of wandered there, but the answer to your question is - Yes, gravity flow will work in a 'bog'. A separate plumbing circuit would be required, however.

Thank you for thru detailed reply. Interesting indeed

 

[Gordo33]

True but wouldn't the resistance of the gravel, roots, debris cut down on that considerably. Maybe I am missing something using only a gravity system with no pump. Sounds like it will be divided to the stream and the bog, not sure on the rate of each from the drawing. I am still of the thought that this would not work ( as least not work as it would need to ) as a gravity flow only system. Am I wrong with this thinking.

Thanks for your input because I have similar concerns with what I am proposing. To clarify I intend to run a 2600gph submersible pump in skimmer 2 to the waterfalls. This would be an independent circuit. Skimmer 1 to the bog if able would be gravity fed. Several members posted concerns about flow out of the bog into the pond including @addy1. My reply was I have a pump also 2600gph , which would be in addition to the pump for the waterfall, to increase the flow through the bog. My original intention was to use the natural forces for water flow to fed the bog.

 

[Gordo33]

The actual gravity fed outflow rate for a 3" pipe is about 3000 gph providing that the inflow (or head) is at least 1" higher than the outflow.

I have a couple questions regarding the 1" differential between the inflow and outflow.
Is the inflow measured at the point the water enters the bog (for ex 2" above bog floor) or the bog floor?
Is the outflow measured at the exit point of the skimmer ( bottom) or the lowest point of the pipe exiting the skimmer?

 

[Meyer Jordan]

The 1" height differential is between the inlet to the 'bog' and the outlet from the 'bog'. The skimmer does not enter into this computation.
Everything I mentioned about flow applies to only the 'bog'. The 1" height is needed to initiate gravity flow. Actually any height over 0 will initiate flow, but at least 1 inch is required to allow what is being pumped in (2600 gph) to drain out. And yes, I would advise pumping the water into the 'bog' as this is the only way that this will work. If gravity feed is used from the skimmer to the 'bog', the the flow rate at the skimmer outlet must be determined and the water level in the 'bog' will need to be lower than the water level in the pond in this configuration. For the 'bog' to drain properly, what it drains into must be lower the the inlet height of the 'bog'. This means that it cannot drain directly back into the pond. This is contrary to the laws of physics.

 

[Gordo33]

It all depends on the desired end result.
True Constructed wetlands are all gravity flow, whether surface flow or subsurface flow. This, and their size and design, determine the overall filtering efficiency. Resident time (amount of time that the water takes to traverse the wetlands) is all important in achieving this efficiency. Typical minimum RT for a constructed wetlands is 5 days.
Of course, the constructs used in ponds that are referred to as 'bogs' are not quite the same thing as a true constructed wetlands, but the same biochemical laws apply.
First, one must decide exactly what the primary function of 'a bog' is to be. Is it mechanical filtration? Biological filtration? Water polishing? Or some combination of these? Each will have a different optimum flow rate.
I kind of wandered there, but the answer to your question is - Yes, gravity flow will work in a 'bog'. A separate plumbing circuit would be required, however.

To clarify my plans :
Skimmer box 1 with course Matala pad(s) -----gravity flow to bog-----to pond. My thought is the bog would be a combination biofilter and polish the water.

Skimmer box 2 with several layers different Matala pads housing 2600gph pump ----- 100 gal stock tank set up as veggie filter waterfall------gravity return via stream to pond

Two separate circuits.
Would this meet the criteria you presented and be successful.
Thanks for your input

 

[Gordo33]

Everything I mentioned about flow applies to only the 'bog'. The 1" height is needed to initiate gravity flow. Actually any height over 0 will initiate flow, but at least 1 inch is required to allow what is being pumped in (2600 gph) to drain out. And yes, I would advise pumping the water into the 'bog' as this is the only way that this will work. If gravity feed is used from the skimmer to the 'bog', the the flow rate at the skimmer outlet must be determined and the water level in the 'bog' will need to be lower than the water level in the pond in this configuration. For the 'bog' to drain properly, what it drains into must be lower the the inlet height of the 'bog'. This means that it cannot drain directly back into the pond. This is contrary to the laws of physics.

Ok I'll keep this simple and use a pump . Thanks for your input

 

[Meyer Jordan]

Ok I'll keep this simple and use a pump . Thanks for your input

Read my edited opening to post number 20.

 

[DeepWater]

No no no! This case of pumpless pond and bog will have no flow!

There has to be a SURFACE water height differential between the 2 bodies of water in order to induce any flow.

Without using a pump, this is stagnant. (Throw out skimmer 2 in this discussion because it is a separate and isolated circuit.)

 

[Meyer Jordan]

No no no! This case of pumpless pond and bog will have no flow!

There has to be a SURFACE water height differential between the 2 bodies of water in order to induce any flow.

Without using a pump, this is stagnant. (Throw out skimmer 2 in this discussion because it is a separate and isolated circuit.)

Exactly!

 

[Gordo33]

No no no! This case of pumpless pond and bog will have no flow!

There has to be a SURFACE water height differential between the 2 bodies of water in order to induce any flow.

Without using a pump, this is stagnant. (Throw out skimmer 2 in this discussion because it is a separate and isolated circuit.)

ok I understand no pump then no flow without a height difference.

Why are you suggesting to throw out skimmer 2? This is set up to be a separate circuit to a 100 gal stock tank that will gravity glow water via a stream back to the pond. the stream will be isolated from the bog.

Skimmer 1 with PUMP will fed the bog which I will raise above the height of the pond and create a waterfall back into the pond.

I already have 2 2600gph pondmaster waterfall pumps so no need for one circuit.
I will to use the skimmer boxes to house Matala pads for mechanical filtration .
thanks for your input

 

[Lisak1]

Why are you suggesting to throw out skimmer 2?

I think @DeepWater meant "throw it out" of the discussion - as in, not part of the equation being discussed.

I've enjoyed reading this. It is good to consider ideas and imagine outcomes before attempting execution. So much better than reading "so, I built this thing... what now?" scenarios!

 

[Lisak1]

Also, as a man-made "bog" aficionado myself, I am happy every time I see someone adding a bog to their pond, whether in a new build or a re-build. (I always add the "bog" for @Meyer Jordan ).

 

[Meyer Jordan]

To clarify my plans :
Skimmer box 1 with course Matala pad(s) -----gravity flow to bog-----to pond. My thought is the bog would be a combination biofilter and polish the water.

Skimmer box 2 with several layers different Matala pads housing 2600gph pump ----- 100 gal stock tank set up as veggie filter waterfall------gravity return via stream to pond

Two separate circuits.
Would this meet the criteria you presented and be successful.
Thanks for your input

Yes, this will work. Because you will be pumping the water into the 'bog', the inlet can be place at any desired level but I am assuming that you are going to pump through a grid of perforated pipe at the bottom of the 'bog' to ensure even water distribution and upflow. So the inlet to the 'bog' would then be on at the bottom of the 'bog'. The outlet or outflow from the 'bog' can be placed according to the desired water level in the 'bog' minus one inch (for a 3" pipe or equivalent.