To bog or not to bog.

[keep'nshallow]

I answered your question briefly on your other thread, but I will add here that we used an Aquascape centipede in both our down flow bog and our up flow bog. We've never had to clean either - pond is six years old.

That is simply amazing!

The centipede is A LOT of money for what seems like just 14" diameter conduit with some slots in it, to an elbow with a 14" diameter riser for clean out. Do you think my above description is accurate? And if duplicated as such would work?

Sorry for my novice questions but:
Where does years worth of feces go?
How many fish do you keep?
How deep x long x wide is your bog(s)?
Do you prefer a up or down bog? Have to admit the down does seem great especially acting as your catch all\screener.

Thanks again for your timely response.

 

[Faebinder]

Feces get broken down to ammonia... ammonia gets consumed by plants... plants grow and die... you remove the dead parts in the trash.. the end.

 

[brokensword]

So, I've been reading all of the posts....I have but one question: Will a bog clog up? All other filtering systems require maintenance, maybe even weekly..? So how can a maintenance plan go from weekly to never? Also Aquascape has a "centipede" for creating a bog filter, has anyone constructed a clean out chamber like this for annual cleaning?

Thanks

I have personal experience that yes, bogs can clog. I guess it would depend on how big the bog is and how big the bioload heading into the bog but I had issues from year four through five (current) when I had to dig up my gravel and manually clean it. Now, I DID have a cleanout stack but didn't think it was sufficient to do what had to be done (backflushing). I've since learned the secret is to use a large volume of water for the backflush (I had this original idea of just using a hose and existing house pressure). That said, Meyer advised I have a prefilter to keep the bog from clogging sooner (if at all), which I've added and it's working great. Installed this prefilter (50 gallon drum 'sock' filter which outlets to the bottom of my bog) early March and haven't touched it yet. I'm hoping I can get through a whole year and then just throw away the filter pad in prep for next year and a new one. We'll see.

So, yeah, clogging can happen. And digging up rocks isn't fun (I found out). I'd advise a prefilter now just to keep the maintenance down to a minimum. Previously, I hadn't touched the bog but now, I'll probably backflush once at the end of the season, just to insure it remains open and isn't more work than it has to be. Backflushing needs a cleanout stack large enough for pump to be lowered to the bottom, and another pump from which you draw your backflushing water (the pond, typically). The idea is to apply large doses of water downwards and have this backflushing water removed a few times by the secondary pump in the bottom of your stack. You would drain the bog once, then backflush to about 1/3 full, pump that out, repeat, rinse, and start again until the outflushed water starts to look as clean as you're expecting. I was told it's typically 3 times. Again, we'll see. Also, one very important aspect of bog building is to slope the walls to a low point where the entry tubing lies. I made a mistake when I dug mine and went straight down. Sloped sides (think 'funnel') really helps the backflushing direct the flow toward the stack area (which should be your lowest point of the bog).

Anyway, that's my experience and I try to pass along what I learned to help others. I think the system I have now will greatly help the bog remain more effective as any sediment of any size gets stopped by the sock filter/drum and now the bog sees mainly water. I'm sure some sediment and debris will still find its way but the yearly backflush should eliminate any major problems. Did I mention digging up rocks isn't fun?

Michael

 

[brokensword]

And just to be complete, I build my bog using large rock (one layer of 4-6") followed by medium sized rock (2" size, about 12" depth) followed by about 2' of pea gravel. My distribution tube is a 4" plastic drain pipe, cut with slots every 6" or so, ended by a cleanout stack large enough to allow a pump to be lowered into it. Very inexpensive and I'd recommend this design. The distribution tube is dug into the bottom of your bog so it sits lower than all the rock above, pitched toward the lowest point, the cleanout stack. Plants are then added to the pea gravel to do what they do. Originally, I had my submersible supply a direct line of water to the bottom of the bog (to the 4" distribution pipe) but now have that supplied by a feed into and out of the new sock drum filter. I was skeptical I'd get enough flow for the bog but it's worked so well I had to cut down the flow to the drum a little as the water was moving too fast up through the rocks/gravel! In other words, now my bot is gravity fed whereas before it was pump driven. Working like a charm, now!

 

[keep'nshallow]

And just to be complete, I build my bog using large rock (one layer of 4-6") followed by medium sized rock (2" size, about 12" depth) followed by about 2' of pea gravel. My distribution tube is a 4" plastic drain pipe, cut with slots every 6" or so, ended by a cleanout stack large enough to allow a pump to be lowered into it. Very inexpensive and I'd recommend this design. The distribution tube is dug into the bottom of your bog so it sits lower than all the rock above, pitched toward the lowest point, the cleanout stack. Plants are then added to the pea gravel to do what they do. Originally, I had my submersible supply a direct line of water to the bottom of the bog (to the 4" distribution pipe) but now have that supplied by a feed into and out of the new sock drum filter. I was skeptical I'd get enough flow for the bog but it's worked so well I had to cut down the flow to the drum a little as the water was moving too fast up through the rocks/gravel! In other words, now my bot is gravity fed whereas before it was pump driven. Working like a charm, now!

Great thanks for adding the second reply as I was about to ask the size of your conduit. It would seem that you took aquascapes recommendation for stones to be added on top of the pipe. I've been reading a lot of these forums and company claims. The aquascapes centipede and clean out section is huge! with a huge price! If memory serves me correct its basically a 14" dia tubing. I was thinking if I could duplicate something close to those measurements I would be safe. They continually talk about how the holes, and I'm sure shear size, of the pipe slows down the flow of water. I believe this is important as the sediments, fish waste and otherwise will settle out in the tube rather than in the gravel bed, what do you think?
So things that I've learned today:
- taper the walls to your bog plumbing
- assure you have a clean out that is large enough for a secondary pump to fit down in
- possibly use a pre-filter
- still so many different recommendations for stone size
- digging in gravel is no fun, lol

Things I still need answers:
- I currently have in mind a 4'x8'x 3'-4' deep bog filtering a 6k-10k gallon pond with fish.
Is this enough bog?
- Would having slenderer bogs half as wide work more efficiently? Be able to channel the water more, or whats best?
- For cleaning the bog plumbing and media has anyone ever added air lines in the media and
or plumbing to help knock lose the matter, just like you see on those blue 55 gal drum filters
I've read up on so much. I would sure think this would loosen things up faster/better.
- Has anyone used a psi washer down the clean out tube again to loosen matter and maybe
use it in the gravel to loosen? Obviously not using the cutting jet.
- The bog should the water be above the gravel or beneath?
- How would you clean a downward flowing bog? All sediments/matter have to go all the way
through the media to reach the clean out tube.

Thanks for the help!
-

 

[brokensword]

Great thanks for adding the second reply as I was about to ask the size of your conduit. It would seem that you took aquascapes recommendation for stones to be added on top of the pipe. I've been reading a lot of these forums and company claims. The aquascapes centipede and clean out section is huge! with a huge price! If memory serves me correct its basically a 14" dia tubing. I was thinking if I could duplicate something close to those measurements I would be safe. They continually talk about how the holes, and I'm sure shear size, of the pipe slows down the flow of water. I believe this is important as the sediments, fish waste and otherwise will settle out in the tube rather than in the gravel bed, what do you think?
So things that I've learned today:
- taper the walls to your bog plumbing
- assure you have a clean out that is large enough for a secondary pump to fit down in
- possibly use a pre-filter
- still so many different recommendations for stone size
- digging in gravel is no fun, lol

Things I still need answers:
- I currently have in mind a 4'x8'x 3'-4' deep bog filtering a 6k-10k gallon pond with fish.
Is this enough bog?

----I believe the number to hit is 10% of your total gallonage for your bog. Obviously, bigger is better as any potential clogging will happen less often. Addy has a very large bog which she's never cleaned. If I'd have had more room, I'd have doubled mine. Still, worked for 3 years with no problem and only when I started losing water from the bog (channeling started and the sides were easiest, which pushed water over my edge because I miscalculated the original overlap). Hence the re-dig. My bog is about 4'x4' and almost 44" deep. I have a 2700 gallon pond.

- Would having slenderer bogs half as wide work more efficiently? Be able to channel the water more, or whats best?

----I'm not sure re this idea; Meyer would be the one to ask.

- For cleaning the bog plumbing and media has anyone ever added air lines in the media and
or plumbing to help knock lose the matter, just like you see on those blue 55 gal drum filters
I've read up on so much. I would sure think this would loosen things up faster/better.

--- sounds like an idea that would work but I just recently learned from a pond installation pro that the trick is to use a lot of volume when backflushing. I mentioned using a pressure unit but he didn't recommend anything but a large volume. Most of your 'clog' is going to happen at the base of your pea gravel so not sure how much effect air into the system would help, but it probably would. If not a lot of extra $$, I'd prob add the lines. See, with larger openings (2 and 4-6" rock) beneath the pea gravel, whatever clogs will have easy paths to being flushed 'down'. As you push the dirty bog water out via the stack/stack pump, you should be able to see how dirty it really is. Repeated flushings should show it getting progressively clearer, with 3 times the typical.


- Has anyone used a psi washer down the clean out tube again to loosen matter and maybe
use it in the gravel to loosen? Obviously not using the cutting jet.

---- already noted above that when I mentioned this to the pond pro, he didn't advise I do the backflushing that way.


- The bog should the water be above the gravel or beneath?

--- just below or barely above. Some think that just below keeps mosquitoes from becoming a problem but I learned they don't usually lay eggs in moving water anyhow, so...mine is just above and it WILL tend to grow different algae which I remove manually. I don't see it as a problem either way. JMHO.


- How would you clean a downward flowing bog? All sediments/matter have to go all the way
through the media to reach the clean out tube.

--- since the detritus would all clog at or near the surface, I don't think you'd 'backflush' as much as stir and filter at the bog's outlet end. Or, use a pump set lower, in the gravel, and as the stirring settles into the depression, pump it out that way. I like the 'upflow' better as when the top gets filled/clogged, there's not much bio-filtering going on anymore. The water will take the easiest route and would simply pour over. With either the pump or my gravity fed system, water is forced through and I think that is more efficient/efficacious.

Thanks for the help!

Quite welcome. I like bogs simply because they work almost automatically and naturally, despite an upflow system isn't exactly 'natural'. Close enough and for 3 years, I got to just 'read' everyone else's filter cleaning stories. Plus, I like the extra planting area!

Michael
-

 

[addy1]

Mine is around 4.5 feet wide, 26 feet long, 2.5 feet deep full of 38000 lbs of pea gravel (delivered by a truck).

I have two, two inch pvc pipes running the length of it. We cut slits in the pipes with a chop saw, faced the slits down. I did put a extra pieces of liner under the pipes so the pounding of the water would not wear the liner.

We got the pond and bog up and running in 2010, I have not touched it since except to purge plant over growth.
I do not drain it or back flush it ever.

The water in places is above the gravel, other places level with it, some places below. The return is a water fall back into the pond.

With the bog as my only filtration I never do anything to the pond. It does not get green water or massive amounts of string algae. I do get string algae is my small slow flow warm ponds. They are only fed dirty water from the big pond.

The water fall rock is around 3 foot long.

This is the 5 foot deep area, you can count the trap door snails on the bottom.

 

[keep'nshallow]

Mine is around 4.5 feet wide, 26 feet long, 2.5 feet deep full of 38000 lbs of pea gravel (delivered by a truck).

I have two, two inch pvc pipes running the length of it. We cut slits in the pipes with a chop saw, faced the slits down. I did put a extra pieces of liner under the pipes so the pounding of the water would not wear the liner.

We got the pond and bog up and running in 2010, I have not touched it since except to purge plant over growth.
I do not drain it or back flush it ever.

The water in places is above the gravel, other places level with it, some places below. The return is a water fall back into the pond.

With the bog as my only filtration I never do anything to the pond. It does not get green water or massive amounts of string algae. I do get string algae is my small slow flow warm ponds. They are only fed dirty water from the big pond.

The water fall rock is around 3 foot long.View attachment 100822


View attachment 100823

This is the 5 foot deep area, you can count the trap door snails on the bottom.View attachment 100827

Thanks, that's terrific!
I just found your Building a bog/pond from the beginning thread (53 pages worth). A lot of great pictures to see your build is awesome. The tractor seems like a must in your location, I have a different rock but beneficial to my cause, we have river rock all over the place! Disturb the ground and you now have a rock garden, lol. I can't wait to get started on my project.
I am a bit confused on your description of the different type of bogs though...do you not have burns under the liner separating the pond from the bog. The way I read your description it sounds as though the divider is inside of the pond, a rock wall. So the water would be pumped in and then leached back into the pond through this rock wall filter. I've always seen a bog as being a separate structure that pours into the pond or pond pours into it.
Thanks for all your words. I have but only 46 pages left on your thread, lol

Good day,
Mike

 

[addy1]

I wrote that up years ago............. and with software updates it has lost some pictures etc.

There are many ways to do one. One is a rock wall or some sort of permeable wall that lets the water just go back and forth.

Mine is a separate structure, the water is pumped in and it flows up then out back into the pond. I have a solid wall between the pond and the bog, it is all one liner though.

 

[brokensword]

(my responses to your last post are inside your quote, KnS; just in case you didn't notice to expand everything. Easier this way...

 

[Meyer Jordan]

From Dictionary.com---

"Filter
noun
1.
any substance, as cloth, paper, porous porcelain, or a layer of charcoal or sand, through which liquid or gas is passed to remove suspended impurities or to recover solids.
2.
any device, as a tank or tube, containing such a substance for filtering."

If a 'bog' is truly a filter, then at some point in time it will begin to clog. The larger the 'bog' the less noticeable this will initially be. It will clog randomly creating what is called 'channeling' where the water flow, because it always takes the path of least resistance, will be observed to stronger in in some areas of the 'bog's' surface than others or as @addy1 described it in her 'bog', "The water in places is above the gravel, other places level with it, some places below.". As the severity/occurrence of this 'channeling' increases overall efficiency of the 'bog' decreases.
Bottom line is that all 'bog' filters and similar filters such as Phyto-filters will require flushing as with any other pond filter, mechanical or biological. The larger the 'bog' in relation to the fish load.and general size of the pond the longer it will take for this 'channeling' to become problematic.There is a positive side to this as the areas that are clogged will become anaerobic and contribute to the denitrification process.

 

[addy1]

or as @addy1 described it in her 'bog', "The water in places is above the gravel, other places level with it, some places below.".

lol that is because I have piled up the gravel high in places, for some plants, lower in other places so the birds have bathing spots. It has been that way since I built it.

 

[Meyer Jordan]

lol that is because I have piled up the gravel high in places, for some plants, lower in other places so the birds have bathing spots. It has been that way since I built it.

My mistake, but you have mentioned in previous posts on other threads that you have some.channeling in your 'bog'.

 

[addy1]

My mistake, but you have mentioned in previous posts on other threads that you have some.channeling in your 'bog'.

My channeling has been my doing. I dug some paths for the water to flow freely between the plants. I don't recall saying the bog was channeling. But could have. I did dig down one time to see what the gravel at the bottom was like, it was nice and clean non smelly.

No indications yet of any blockage issues. But then again I do not suck the water from the bottom of the pond, do have a leaf basket before the pump. I don't want to drawn in the bottom critters, snails and whatever else lives down there. The water going into the bog is pretty debris free.

I do get a nice layer of fine dirt on top of the gravel, every year I think of taking a wet dry vac and sucking it off, every year never do.

 

[Lisak1]

We turned the pump off for a few hours today to do a little repair work and it was hilarious to watch all the frogs vacate the bog. Our bog has a couple of inches of water over the gravel until the pump goes off. Today they were all like "what the heck? Who turned off the water?" As soon as the pump went back on, they all headed back to their stations. So fun to watch!

If a 'bog' is truly a filter, then at some point in time it will begin to clog.

What about biological filtration? If your "filter" is removing things from the water that the naked eye can't see is it still subject to clogging?