Bog pump vault / centipede

[Gordo33]

@Lisak1 uses this in her bog. Does anyone else have experience using this set up with their bog?

I want to incorporate a bog to assist filtering the pond which will include 3-4 koi and a 20-30 goldfish. My concern with a bog and koi is the potential for waste build up in the pea gravel causing channeling,anaerobic bacterior and a breeding place for parasites. I was trying to figure a way to create an open chamber below the pea gravel to allow the debris to settle out of the water column and not head up into the gravel. Lisak1 mentioned a vault chamber in her showcase. Not knowing what a pond vault was I assumed she created what I envisioned.

Aquascapes also has AquascapePRO Aquablox Modular Water Storage System - Small. The dimensions are 26"L x 13"W x 9.5"H.

This could create the open chamber with rocks /pea gravel siting on top of the modular water storage system. Debris would settle and then could be flushed out.

Any input would be greatly appreciated as I am driving myself crazy with planning the pond renovation

 

[Meyer Jordan]

I have constructed both types.
The secret when using all rock is to start at the bottom with large (8" x 12") rock with a layer of cobbles (4" x 6") as a second layer followed by a layer of large gravel (1" x 2") covered by a shallow layer of pea gravel.
If you are primarily looking more for polishing the water then the use of the matrix blocks ( a.k.a.ResCubes a.k.a.Aquablocks) are used with up to a 6" layer of gravel over them. I normally used Egg Rock (Potato rock) instead of pea gravel. Not that much difference in SSA and does not clog as easily as pea gravel.
Here are a couple of photos of a dual chamber phyto-filter that I constructed to polish water for an earthen-bottom pond. (Note the gravel size)

 

[Gordo33]

I have constructed both types.
The secret when using all rock is to start at the bottom with large (8" x 12") rock with a layer of cobbles (4" x 6") as a second layer followed by a layer of large gravel (1" x 2") covered by a shallow layer of pea gravel.
If you are primarily looking more for polishing the water then the use of the matrix blocks ( a.k.a.ResCubes a.k.a.Aquablocks) are used with up to a 6" layer of gravel over them. I normally used Egg Rock (Potato rock) instead of pea gravel. Not that much difference in SSA and does not clog as easily as pea gravel.
Here are a couple of photos of a dual chamber phyto-filter that I constructed to polish water for an earthen-bottom pond. (Note the gravel size)

Meyer, thanks for the input and pictures. The bogs you constructed look great.
Current advise when building a pond is not to place rocks in the bottom of the pond because it just becomes a place for waste to accumulate and is difficult to clean. Then over time you have potential issues with anaerobic bacteria and hydrogen sulfide gas. Why is this scenario different than with a bog unless the water being sent to the bog is prefiltered? This question is what currently has me going back and forth with incorporating a bog. When reading this forum everyone who has a bog seems to be very happy and report low maintenance. It also seems that the majority of ponders here have low fish loads and or other systems in conjunction with the bog which maybe contributing to the bogs success.
Then I go to one of the dedicated koi sites and bogs get blasted by the majority, there is a few who bravely defend them, because of the muck and all the other potential nasties. Many on the koi site have stated they were tired of pulling the gravel every few years to clean it.

I certainly don't want to add something that I will need to tear apart every few years. So I thought the matrix and chamber system would allow for sediment to settle and be flushed. Aquascapes has a video that states the design of the centipede allows water flow to be slowed down by 93% thereby giving particles in the water a chance to settle in the chamber minimizing build up in the gravel. Do you believe their claims are possible?

One final question how would you rate the stock level of a 3000 gal pond with 4 koi ,20-30 goldfish and 2-3 frogs?

 

[Meyer Jordan]

Current advise when building a pond is not to place rocks in the bottom of the pond because it just becomes a place for waste to accumulate and is difficult to clean.

That "current advice' is not quite accurate. Every pond that I constructed in the 20 years that I was active in the pond trade had gravel covered bottoms with one exception. And that was only because I was the sub-contractor for a landscaper that knew nothing about water features or ponds.

Then I go to one of the dedicated koi sites and bogs get blasted by the majority,

In my experience, I have found that the Koi Kichi mentality and mindset is that if there is a hint of something being a 'natural' process it is then taboo. Thankfuly that mentality is dying off somewhat.

Aquascapes has a video that states the design of the centipede allows water flow to be slowed down by 93% thereby giving particles in the water a chance to settle in the chamber minimizing build up in the gravel. Do you believe their claims are possible?

I have used the Aquascape snorkel and Centipede on many projects and they serve the purpose well, but unless Aquascape has completely re-engineered the Centipede in the past few years, this claim is bunk.

Why is this scenario different than with a bog unless the water being sent to the bog is prefiltered?

It really is no different.Even with pre-filtering (which is universally recommended) sediment will still accumulate at the bottom of 'bog' or phyto-filter just at a slower rate. And all of the talk about hydrogen sulfide and anaerobic bacteria is 'chicken little' talk. Both of those elements occur in every natural pond and fish thrive. In fact some anaerobic bacteria are necessary for denitrification.

One final question how would you rate the stock level of a 3000 gal pond with 4 koi ,20-30 goldfish and 2-3 frogs?

Probably will not cause any issues but to be sure I would need to know the sizes of the fish and what typical biofiltration is being provided other than the planned 'bog' or phyto-filter.

Did I miss anything that you had a question on?



.

 

[Gordo33]

That "current advice' is not quite accurate. Every pond that I constructed in the 20 years that I was active in the pond trade had gravel covered bottoms with one exception. And that was only because I was the sub-contractor for a landscaper that knew nothing about water features or ponds.







It really is no different.Even with pre-filtering (which is universally recommended) sediment will still accumulate at the bottom of 'bog' or phyto-filter just at a slower rate. And all of the talk about hydrogen sulfide and anaerobic bacteria is 'chicken little' talk. Both of those elements occur in every natural pond and fish thrive. In fact some anaerobic bacteria are necessary for denitrification.



Probably will not cause any issues but to be sure I would need to know the sizes of the fish and what typical biofiltration is being provided other than the planned 'bog' or phyto-filter.

Did I miss anything that you had a question on?



.

Thanks you answered all the questions from my post BUT.....
In a small bog 4W x 12L x 1.5D would you use the vault and chamber or just the various size rocks as you outline in this thread? Can you please explain why. If using the chamber /vault set up can that be DIY'd using 12" catch basin with PVC? Cost would be 1/4 to a 1/3 less.

My stocking question assumes the fish reach their maximum size over time( starting koi 5-8" range). For bio filtration I plan on using the same set up I have on my current goldfish pond plus the bog. I have a 100 gal stock tank filled with yellow flag iris that flows into a 2 tiered planted stream total length 9 ft filled will 3-5" river rock and the streams perimeter has pea gravel and is planted. The pond itself has planted water lilies and submerged plants( that need to be thinned out). Where the stream enters the pond I have a pond planter basket filled with pea gravel. The total water volume approx. 1300 gal with 25 or so goldfish from a couple inches to several that are 8-9" range. The water parameters have been all 0's and no algae blooms the last 2 springs.( I learned string algae in the winter and early spring is my friend). The pond is entering its 5th season.
One big difference with the renovation and adding Koi is I would feed the fish. Currently the goldfish and other inhabitants live off the pond. So I guess their would be an increase bio load from any uneaten food.
I would monitor ammonia regularly and add a moving bed bio filtration unit if necessary.

I want to do this right so the fish thrive instead of just surviving. Any additional input regarding my pond renovation would be greatly appreciated.

One last question. How did you separate my post into different parts and add a response to each part?

 

[Meyer Jordan]

One last question. How did you separate my post into different parts and add a response to each part?

Highlight the desired passage as you would if you were going to copy and paste. Do not click the right mouse button. A little pop-up balloon will appear that says reply. Left click on this.The passage will now appear in the comment text box. Just as if you clicked reply for the entire post.

 

[Meyer Jordan]

In a small bog 4W x 12L x 1.5D would you use the vault and chamber or just the various size rocks as you outline in this thread? Can you please explain why. If using the chamber /vault set up can that be DIY'd using 12" catch basin with PVC? Cost would be 1/4 to a 1/3 less.

I would not necessarily call a 4 x 12 x 1.5 'bog' small.
Whether you install a full 'bog' with varying size rock or a phyto-filter using the matrix cubes you will need a vault of some sort for flushing the system when it is needed whether it is every week or once every 5 years. You will need access. You can also DIY the centipede using standard corrugated drainage pipe with one end capped. Honestly for your purposes I would opt for the phyto-filter as the plants are the real workhorses here. Yes, it will probably cost more for the matrix cubes than the rock but you will greatly reduce the incident of clogging and channeling and as a result maintenance will be minimal.

 

[urglik]

That "current advice' is not quite accurate. Every pond that I constructed in the 20 years that I was active in the pond trade had gravel covered bottoms with one exception. And that was only because I was the sub-contractor for a landscaper that knew nothing about water features or ponds.

could you elaborate on why you like a layer of gravel on the bottom of the pond and do you speak of pea gravel?

 

[Meyer Jordan]

could you elaborate on why you like a layer of gravel on the bottom of the pond and do you speak of pea gravel?

Don't want to hi-jack @Gordo33's thread with a lengthy response. Simple put, it helps to create (or approximate) the conditions that exist at the bottom of a natural pond....what is called the Benthic layer. It is an integral part of the biochemical cycles of an aquatic eco-system. A major player in the Nitrogen and Carbon cycles.

 

[Gordo33]

Don't want to hi-jack @Gordo33's thread with a lengthy response.

Feel free to hijack and give a lengthy response I'm interested in learning how the gravel on the pond bottom is benifical.

 

[Meyer Jordan]

Feel free to hijack and give a lengthy response I'm interested in learning how the gravel on the pond bottom is benifical.

The question is-

Is gravel on the bottom of a constructed pond (lined or concrete) beneficial?

Answer-
Is the bottom of an earthen pond beneficial?

No, I am not being a smartie or smug. Let's look a little closer at this.
The bottom of a natural pond may be composed of varying substrates but will always have sediment of varying thickness covering this substrate. This sediment itself may be composed of varying ingredients based on the cause of deposition, run-off, wind-blown, etc. The composition and depth of this sediment will in turn influence the biodiversity of animal and microbe specie that call it a home. It is this animal and microbe diversity (benthos) that provides partial benefit to the aquatic ecosystem.

The placement of a layer (max. 2") of gravel (preferable nickel, quarter size) on a constructed pond's bottom provides:
-Additional SSA for increasing nitrification efficiency of the eco-system.
-Additional surface area for algae colonization thus augmenting Oxygen production and the base of the food chain.
-Habitat for many specie of organisms (benthos) that would not colonize elsewhere in the pond.
-For the creation of anoxic areas or pockets where denitrification can take place further enhancing the equilibrium of the pond.
In a pond that houses Koi, it also provides a direct source of natural food for the fish as Koi (Carp) are bottom-feeders. And because of this bottom-feeding, the gravel is constantly being stirred up and re-arranged so that anaerobic conditions (though really not a true problem) will only rarely develop.
The chart below illustrates how the Nitrogen cycle is affected.

This is just a general overview. As is with other aspects of a pond, flow rate, level of supplemental biofiltration, level of mechanical filtration, and fish load will affect the biochemical processes of a bottom gravel layer.

 

[Gordo33]

you will need a vault of some sort for flushing the system when it is needed whether it is every week or once every 5 years.

When flushing the "system" is just the slits or holes in the piping being flushed to free up clogged areas throughout the pipe? I can't imagine there would be enough pressure to push sediment out of the rocks/gravel.
I have not seen any bog builds that have an exit or drain. So does all the sediment flushed out of the pipe(s) end up in the rocks/gravel? Would a drain port exiting the side of the bog be helpful when flushing the system?

 

[Meyer Jordan]

When flushing the "system" is just the slits or holes in the piping being flushed to free up clogged areas throughout the pipe? I can't imagine there would be enough pressure to push sediment out of the rocks/gravel.
I have not seen any bog builds that have an exit or drain. So does all the sediment flushed out of the pipe(s) end up in the rocks/gravel? Would a drain port exiting the side of the bog be helpful when flushing the system?

When flushing any type of water filtering system, the flow is reversed. In the instance of an upflow 'bog', water is directed downward through the gravel dislodging accumulated organic debris in the process. This debris laden water is then removed from the 'bog' by positioning a pump at the bottom of the vault thus removing this waste water. Depending on the amount of debris this flushing may require repeating until a desired clarity in the waste water is achieved.

 

[brokensword]

Gordo; let me add a bit more to what I've learned as I'm currently struggling against this problem as well. What I've learned is that it is best done (the flushing) using TWO pumps; one in the cleanout stack, and one in a large source of water (the pond). I was told; drain (using a pump in the cleanout stack) the bog down to within a foot or so of the bottom, then force (with the other pump) a large VOLUME of water top down into the pea gravel. It's the volume that is your friend. I mistakenly thought I'd succeed with a hose from the house but learned otherwise. I was told to force the water down until the bog is half full or so, then stop the flush, turn on the stack pump, and once again take the level to within a foot or so. Doing this minimizes both time and amount of water you'll use when backflushing. This info is from both Meyer as well as Dave from thePondProfessional.com who really helped initially and now with tweaking what I've created.

Btw, my bog was built as Meyer has stated; large rocks on bottom, smaller next, and pea gravel at the top.

Also, and critically (since I didn't understand well enough in MY bog design originally) the SHAPE of your bog should be like a funnel. This helps direct the backflushed particles TOWARD your distribution pipe, which lays on the bottom (in a trench of its own and it basically below your bog bottom). This distribution pipe ends itself IN your cleanout so when you put a pump there, and with the walls of your bog sloped like a funnel, as you backflush, the clogging moves toward the area you're sucking, and then out with your pump. I was told this might take a few flushes depending on how clogged it is. I got about 3 years out of my bog before issues creeped in and the last two years I had to cut the flow (less/slow) because the water was forcing itself along the bog walls an up the cleanout instead of through the gravel. I felt I had to totally dig the bog out and it was a lot of work. There's a thread I started to share my experience and it's the basis of my idea to make a pre filter (at Meyer's suggestion). I'm fine tuning now and hope to have it up and running in a couple of weeks. My plan is now to flush the bog each fall, after I cut the plantings down since it's the best/easiest time to work on it and it'll be ready then for spring. Should mean NO MORE DIGGING!

At least that's how I understand it and will be doing in the future. In addition to this, and with Meyer's help, I've been playing around with a design for a drum filter which will (hopefully) be a bog prefilter, thus lengthening out my next 'bog cleanout. If this works as hoped, I'll post some pics and maybe it will help others with their design. I'm doing this by incorporating the drum prefiliter into an existing bog system so others can probably retrofit the design too. Just need some room for a large drum filter within your pondscape.

Michael

 

[Mmathis]

What an interesting thread! We are getting close to adding a bog as the main filtration system for the pond. I've often wondered about the "snorkel" system. @Gordo33 what I have on my smaller bog [the one that goes to the box turtle habitat and is about 6'x3'] is 2 "clean-out" pipes, one on each end of the bog's tubing. I have a threaded pipe and a cap on each pipe that I can remove for flushing. And I know what you mean about the dedicated koi sites... You have to remember that most of these folks have a totally different attitude toward what they view as a pond. For their koi, they go to elaborate lengths to maintain a pristine environment -- but then, too, some of them have very expensive fish, so...... The idea of a "garden pond," can likewise be something they tend to stay away from. "Pond" is for koi / "separate pond" is for plants. So, as far as what's the best thing for your/our fish [bog or no bog] is totally up to each to of us and what we want from our pond..... So, don't get confused. One isn't necessarily better than the other, only DIFFERENT!