Bog Filter - Thoughts on Sumps/Settling Chambers

[Karl_S]

Is the consensus here that for a bog filter a sump area below the stone, maybe using something such as the Aquascape AquaBlox, is not necessary? It seems there are 2 schools:

• Add an area for water to be stored and slow down the flow to allow particles to settle out. This sump is below any stone - clean this out on a regular basis which varies from yearly to only when needed and seems to be a factor of sump area vs pond size. Not sure how you clean it out other than flushing it with a high volume of water since these boxes block any ability to do more.
• Use perforated pipe and stone without any other sump area. Add a clean-out to flush these with water as well.

Frankly, I do not have enough area to use just a bog filter so I will probably do a bog area and a traditional filter on a waterfall. I am just trying to figure out my needs and project a cost.

Also, is there a minimum recommended width for a bog filter? Ideally I would have about 18" x 210" (1.5' x 17.5' - .5m x 5.3 m) with water traveling the long dimension to the pond. I could make it a little narrower and put a stream next to it so the water from the far end is not going through as much rock, but I am looking at a patio area here and have a hemlock tree I do not want to encroach on. I do have about a 4' x 5' (1.2m x 1.5m) area where I could put the bog. This also puts it at the top of the waterfall area.

I expect the pond to be roughly 13' (4m) wide with one side at 15' (4.5m) and the other at 10' (3m). Think a 13'x10' rectangle with a triangle on one of the 13' sides adding 5' to the rectangle's 10' base.

Looking at the thoughts of those here with experience. Mine all comes from aquariums! Also, in case it makes a difference, I am in the Mid Atlantic area of the US. Probably 90 minutes from @addy1 based on her signature, but a slightly warmer area.

Karl S

 

[addy1]

Mine is only pea gravel and pipes. I did not do settlement chambers etc. Mine works just fine. It is big, it is deep 2.5 feet of pea gravel. It does not need to be that deep, imho, you do not need settlement chambers etc. But others have them and like them.

I also do not have a clean out and have never seen a need for one in the 10 years of running.

My hot tub bog is a planter box with water flowing up via tube from the bottom, no pipe.

Any bog type with gravel/rocks something and plants will help the pond.

 

[combatwombat]

I have a totally unfounded theory that is completely untested, and it is:

If you have a low fish load, pre-filter your water and pump it slowly through a really big bog (relative to your pond) it might perform indefinitely. If you change one of those variables, you might be glad you have a way to backflush it.

The serious fish-keepers I know (I am not one) believe that any filter that can't be backflushed is not worth having.

BTW, you can create a backflushable bog regardless of what style you use to build it, and aquablox are just one of a few different ways that you can add settlement area.

 

[GBBUDD]

I have both Bogs on my pond the aquablocks and the gravel only bog. This is how i see the aquablocks yes they are designed where it is a settling area for heavy debris to sit and drop out of the water column. BUT MORE IMPORTANTLY i see that area as a HOTEL there are soooooooo many aquatic creatures out there that man has noooooo clue or understanding of. But after working along side environmental scientists for many years. Much of the understandings to nature have rubbed off. That being said i see it as say a mass of algae gets sucked into the pump and pushed to the bog it makes it way into this area where Light is non existent and that alone will break down algae and when it does it falls or gets hung up on the frame of the blocks where the host of aquatic microbes insects biotopes and insects not to mention i have found baby koi in my snorkel . Many of these creatures cant survive in a mass of gravel and where there is no predator's and they thrive. If you go to a stream and look at the bottom you'll see all kinds of tubes tunnels and channels. So i do feel your giving all the scenarios a place to thrive and grow,

 

[Jhn]

@Karl_S to clean out the settlement area there should be a snorkel reaching below the aquablox, this will be the lowest area in the bog, where all the silty material settles out of the water column and collects. This can then be pumped out, via the removable top on the snorkel.

IMO, as @addy1 said-any size bog is better than no bog, you just need to adjust your flow accordingly to slow the flow through down in the bog to get plenty of dwell time.

 

[Karl_S]

I believe the bigger benefit here comes down to the creation of a larger water mass. The larger a pond, the more stable, due to a larger water mass. With an underground chamber, you are putting a volume of water in an area where external pollutants and other forces do not reach it as well as increasing your water to fish ratio.

I have both Bogs on my pond the aquablocks and the gravel only bog. This is how i see the aquablocks yes they are designed where it is a settling area for heavy debris to sit and drop out of the water column. BUT MORE IMPORTANTLY i see that area as a HOTEL there are soooooooo many aquatic creatures out there that man has noooooo clue or understanding of. But after working along side environmental scientists for many years. Much of the understandings to nature have rubbed off. That being said i see it as say a mass of algae gets sucked into the pump and pushed to the bog it makes it way into this area where Light is non existent and that alone will break down algae and when it does it falls or gets hung up on the frame of the blocks where the host of aquatic microbes insects biotopes and insects not to mention i have found baby koi in my snorkel . Many of these creatures cant survive in a mass of gravel and where there is no predator's and they thrive. If you go to a stream and look at the bottom you'll see all kinds of tubes tunnels and channels. So i do feel your giving all the scenarios a place to thrive and grow,

 

[Lisak1]

you are putting a volume of water in an area where external pollutants and other forces do not reach it as well as increasing your water to fish ratio.

Well to a degree, yes. However you're circulating that water so it's definitely not protected from those other "forces".

 

[poconojoe]

Well to a degree, yes. However you're circulating that water so it's definitely not protected from those other "forces".

My exact thoughts.

 

[GBBUDD]

a volume of water in an area where external pollutants and other forces do not reach it as well as increasing your water to fish ratio.

Yes it does that . The larger the pond the more stable the pond will be. It also helps to keep the pond cool as that water is below grade . I was talking strictly bio load

 

[Karl_S]

Well to a degree, yes. However you're circulating that water so it's definitely not protected from those other "forces".

This is true. Protected from other forces was the best I could come up with regarding the area being a place which allows for an increase in water volume while also not increasing the actual pond area. And that it does such using a protected area. I did not mean that the water was stagnate as that would introduce other problems as well as void the idea that we are increasing the water's mass.

 

[Lisak1]

Gotcha. And yes - it increases your pond volume. But remember that any plumbing failure or power outage means your pond volume is suddenly decreased, if you don't have a way to keep the water circulating. We learned that the hard way.