back-flushing a bog: how to do?

[bobchapman]

I've seen several comments in this forum indicating that people have some provision in their bogs for back-flushing (cleaning) them.
I'm interested in building a bog for a new pond. I'm assuming that the bog will have water coming in at the bottom of the bog through PVC pipes with slots or holes in them, which will distribute the water into the bottom of the bog sort of uniformly. This "dirty" water would then flow upwards through the gravel and back to the pond via spillway.
Can someone explain to me how one "flushes" the accumulated waste out of such a bog?
Thanks
Bob Chapman

 

[dieselplower]

Bogs are not usually backflushed.

 

[Mucky_Waters]

Check out this thread https://www.gardenpondforum.com/topic/10937-this-is-why-im-not-a-fan-of-bogs/?hl=bogs
There is a video of someone rinsing out a sort of bog, it gives you a pretty good idea of the sort of foul crude that accumulates in there.

 

[addy1]

Mine is a big bog, the only filtration for my pond.

We put in bottom pipe, that goes to a ball valve outside of the bog, to be able to drain it. A year ago, after a lot a posts about how foul they can get, I wanted to see how bad the bog was. I used a high pressure hose to push water through gravel I.e. backflushing, with the drain wide open, I didn't get much of anything out except clear looking water, no foul stink, no massive amount of muck. I do not have the external pump intake on the bottom of the pond, it is about a foot up. I did not want to suck up the snails, dragon fly larvae, etc.
With my set up I just net the bottom of the pond to remove muck. I went to net it for the first time in 1.5 years, quit after the first few attempts, not enough stuff on the bottom to mess with.
A year before I netted the bottom, got only 1/2 of a 5 gallon bucket of muck.

My pond water stays green water and string algae free. Water tests have been perfect. The small, slow flow, non bog filtered ponds do get some string algae, but never green water.

 

[Mmathis]

Good question, and I've wondered the same thing. Our bog is still on the drawing board, but have been trying to figure out my "system" of tubings, valves, etc. for the past 6 months. If you'll check out ADDY1's post, pinned in "POND CONSTRUCTION," she talks about that.

And Diesel, maybe not backflushed as often and like you would a regular filter, but still need that option available. If for no other reason than to be able to clear the tubings if they ever clogged with gravel.

Since being a pond owner, I've read many stories and watched many videos regarding bogs, veggie filters, whatever. Some people say that they NEVER have an accumulation of crud. Yet have also seen videos that show just gross, gross, gross stuff being flushed out. Now, I'm sure there are variables at play, such as [maybe] the depth of the bog, or the total "crud" load level in relation to the bog's surface. Don't know. But I WANT to have the ability to back-flush if I ever need to.

 

[Mmathis]

Addy, looks like we were posting at about the same time, LOL

 

[addy1]

Addy, looks like we were posting at about the same time, LOL

one finger typing on honies tablet, up in the mountains using our phone hot spot for internet,, got to love technology. I could use the speak typing, but hate talking out posts when honey watching tv. We have a small place up in the pa mountains, sitting here wind blowing, wind chill 33 or so, rain coming. Watching deer and looking over the valley



I am comfy enough with my bog filter I can ignore the pond almost all summer. Most work I do is clean the skimmer and leaf basket, off and on, maybe once a month unless the maple seeds are falling.

 

[mrsclem]

I am in the process of moving our bog. Made a mistake on the install and it leaks. Taking out the plants and gravel is NOT fun. I will install a drain for flushing mine out when we redo. I'm guessing this will mean cutting a hole in the liner for the drain. Any input on this would be appreciated.

 

[bobchapman]

Quote from Addy1: "We put in bottom pipe, that goes to a ball valve outside of the bog, to be able to drain it. A year ago, after a lot a posts about how foul they can get, I wanted to see how bad the bog was. I used a high pressure hose to push water through gravel I.e. backflushing, with the drain wide open, I didn't get much of anything out except clear looking water, no foul stink, no massive amount of muck. I do not have the external pump intake on the bottom of the pond, it is about a foot up. I did not want to suck up the snails, dragon fly larvae, etc.
With my set up I just net the bottom of the pond to remove muck. I went to net it for the first time in 1.5 years, quit after the first few attempts, not enough stuff on the bottom to mess with.
A year before I netted the bottom, got only 1/2 of a 5 gallon bucket of muck."

Yeah, you're doing what I want to do: major part of filtering done by a bog. Though I'm thinking of adding a settlement chamber between pond and bog to filter out the heaviest "stuff". And I definitely will have a bottom drain, just in case of need: easy to add during construction, impossible later. I also plan on having the flow out of the bog, back into the pond, near the top of the gravel bed so that the water is forced to go through the gravel to get out of the bog.

When you say you used a "high pressure hose", do you mean just a garden hose attached to domestic water supply (well or municipal supply), or do you mean a power-washer sort of thing? or maybe a pump drawing from your pond????

Thanks for your input and that of everyone else who responded. I'm trying to get a handle on all this, and experiencing the usual number of conflicting stories as to what works and what is a disaster. I'd prefer NOT to have to build this thing twice because of making stupid errors the first time!!

Bob

 

[bobchapman]

To Mrsclem: There are many articles here http://www.koiphen.com/forums/forumdisplay.php?66-Pond-Construction-and-Filtration on installing bottom drains in ponds with liners. BDs are viewed as the only reasonable way to go in the Koiphen world.

 

[bobchapman]

Bogs are not usually backflushed.

Do you have direct experience with a non-flushed bog, and how has it worked for you? Is the pond water clean? do you get a lot of "crud" in the bog, as some report? Do you recommend bogs as a good filtering mechanism?
Thanks for you input.
Bob

 

[dieselplower]

I have a bog of sorts. You can see the two containers on the edge of the pond? I consider the smaller one a small bog filter. both containers are filled with gravel and both are upflow filters. I can clearly see the bottom of my pond 4.5 feet down. I plants that container about 6 months ago and the roots grew so fast I had to yank a plant to stop it from overflowing. And WOW did that turn loose a lot of debris that otherwise remains trapped in the filter. The filters retrapped all that debris in a few hours.I am very pleased with it but only have1 year under my belt.

 

[bobchapman]

I have a bog of sorts. You can see the two containers on the edge of the pond? I consider the smaller one a small bog filter. both containers are filled with gravel and both are upflow filters. I can clearly see the bottom of my pond 4.5 feet down. I plants that container about 6 months ago and the roots grew so fast I had to yank a plant to stop it from overflowing. And WOW did that turn loose a lot of debris that otherwise remains trapped in the filter. The filters retrapped all that debris in a few hours.I am very pleased with it but only have1 year under my belt.

Thanks Dieselplower, It's always good to hear from someone who is actually doing whatever is under discussion.
I think that I'll plow forward with my plans for a bog as my major filtering.

 

[addy1]

I don't know how to do replies on this tab it does not go to the bottom to reply, honies tab.
So at bob, this it's 4th summer, 200 plus fish and other stuff in the pond, critters. 8 other small ponds in the same loop.

With all the negative I was reading I took a power washer, gas, blasted the gravel with it. Some pea gravel type dirt came out, not much, no yucky yuck. That was last year. I did not clean the whole bog just a small area as a test. Other than that I have not cleaned it at all. When I pull plants it does really muck up the pond water with fine dirt which clears within a few hours. Makes it so dirty you can't even see the fish.

We did not prewash the pea gravel, too much, on a well and a very dry summer.

My previous ponds had small bogs I did not clean often, maybe once a year.6

I love my bog, makes pond care so simple, no filters to clean, no fuss, do need to yank plants now and then they grow so well. The frogs love to live in it. The water is like dp's crystal clear you can count the snails 5 feet down.

I would never do another pond without one.

 

[bobchapman]

So at bob, this it's 4th summer, 200 plus fish and other stuff in the pond, critters. 8 other small ponds in the same loop.

With all the negative I was reading I took a power washer, gas, blasted the gravel with it. Some pea gravel type dirt came out, not much, no yucky yuck. That was last year. I did not clean the whole bog just a small area as a test. Other than that I have not cleaned it at all. When I pull plants it does really muck up the pond water with fine dirt which clears within a few hours. Makes it so dirty you can't even see the fish.

We did not prewash the pea gravel, too much, on a well and a very dry summer.

My previous ponds had small bogs I did not clean often, maybe once a year.6

I love my bog, makes pond care so simple, no filters to clean, no fuss, do need to yank plants now and then they grow so well. The frogs love to live in it. The water is like dp's crystal clear you can count the snails 5 feet down.

I would never do another pond without one.

Great, that sounds like what I want to do also. And particularly to have a place for plants, frogs, maybe snakes! Thanks for the details -- It helps me to be confident in going forward.