Bog building, also called upflow filter, eco filter, wetland filter

[nomadh]

Mine has been turned off during the hot of summer for a day or so. Turned off for 4 months over winter. I turn it back on, NEVER have a fish kill, never. The water ( in the spring) goes crystal clear within a few day from the winter murky look. I never get green water, minimal string algae. Do nothing but yank plants when they over grow.

I had a small bog on another pond it did just as good, Arizona.
In 2010 when I was researching the best way to build my pond here, I read a lot of posts from monster pond builders. The bog was highly talked about. I did not follow the "rules" 12-18 inches deep, etc, mine is about 2.5 feet deep. I also have high flow through mine, except for a small diversion to another pond all of the flow from my 6800 gph pump is sent through it.

I have never regretted having it, the fish and pond do great.

Not the best picture, this is the flow from the bog. My anti heron net is falling apart waiting for a new one to get here. It also weeps over the bog wall here and there. That rock is around 3 feet long.
View attachment 137220

You have 2.5 ft deep gravel for your water to upflow through as a filter? On the one hand the more media the longer it takes before a problem will show like clogging and channeling. The downside is how much shovelling of gravel and where to put it if there ever is a problem you need to go down there to fix and how do you not destroy the liner doing it? Don't get me wrong if I bought a house with your setup I'm sure I'd love it and use it but I would also have an exit strategy if something ever did go wrong. I'm just a worrier. Or too lazy to accept even a 20+ year maintenance cycle when it comes to shoveling gravel

 

[Jhn]

The biggest issue of both will be gluing the new stream liner to the old pond. Maybe rubber cement or flexseal? Anyone know the best way currently for rubber liner?

Best way to do it is seaming the two liners together with the proper seaming materials for your liners , other ways will fail.....There is a detailed thread stickied at the top of this forum section on how to seam epdm liners together by @GBBUDD

 

[nomadh]

@nomadh - I may have misread, but did you say your MILs waterfall falls ON TOP of the bog? If so, that's a whole other animal.

Gravel is critical to an up flow bog - it slows the water and gives the bacteria surfaces to colonize. Otherwise you just have a heavily planted pool... which is great, just not the same thing. You have plants absorbing nutrients, but you can get that by planting your pond. You aren't colonizing bacteria, which is the magic underneath the plants in a gravel bog.

True, the whole thing is bassackward. I actually have a fall pipe going into the bog for aeration and then that water overflows back to the pond. Right now I am breaking a main rule and pumping directly from the pond into the bog. The rule is never chop up the solids to feed the algae and make it harder to filter the water later. Always gravity feed the first filter, be it settling, bog up or downflow, gravel or not. I just don't want gravel as that first filter either because I don't want to ever clean it The whole thing is horrible.

 

[GBBUDD]

I pump directly to my bog from the pond but it seed a settling chamber first

 

[nomadh]

you know most koi clubs/associations operate with the idea upflow wetland filters won't work, right? That's the way most 'old timers' have always done things, so bogs are anethema to them. Thing is, how do you explain the succes many are having here on the site? Now, some don't have koi but many do and their ponds are doing fine with bog filtration. Better than ever, for some. Most here have garden ponds, not dedicated koi ponds, so maybe that's the secret? Some turn off their bog pumps for the season and start them up and there's no one reporting problems. The gravel you want to eschew is where the bacteria colonizes. Your plants are only taking up the nitrates in the water, not the nitrites nor ammonia. So, hard to see how having all that surface area in a bog as not beneficial. Still, if you've got it working without, more power to you. Obviously, you have enough surface area somewhere in your system to provide for your current fish load. But be careful as your pond fish grow/propagate as that's when we get the most posts with problematic situations.

No, most of the old timers, 50+year koi members and article authors, have the older style upflow design. It feels very natural and fits many pond designs and can certainly work with great results if well built. Some didn't like plants as the dying parts could cause more bioload and maintenance. I think a bog, nearly any bog is a huge addition as a filter for water quality. And yes with enough gravel it will have enough biofiltering to be very healthy. In fact if the gravel was kept in a bucket above water level and pre filtered water were sprayed into it at a rate it could drain back out it would be probably as good a biofilter as may exist. And with how I see trickle towers work it could very possibly go literally forever without ever needing a cleaning . But I still wouldn't WANT to use rock. somewhere inside the filter even then it could start to channel and clog. Without digging it out you'd never know. But being wet/dry the surface area would be outstanding i'm sure. but under water it would be many times less efficient. If you can turn it off for a long time without getting oxygen to it and the fish are ok when it turns back on then that's a great test that the bacteria are munching away and you must have very little detritus down there. Maybe the only aerobics being pumped out would be the aerobic bacteria that died while being oxygen starved. Probably not enough to be any problem.
Yes a good filter definitely needs oxygenated surface area. My pond is pretty good but I am considering adding to the biofilt as I have added some big fish recently. My MIL pond definitely needs more biofilt. Probably one similar to mine but because of the location it will starve out the current gravelless bog plants we love.

 

[nomadh]

@nomadh Look at the mechanics of a bog. Most of us use up-flow bogs where water from the pump is pumped through a manifold (of one type or another) at the bottom of the gravel bed. Water flows upward, through the gravel and past the plant roots. Yes, there might be channeling, but if the bog is plumbed correctly, and maintained (plants cultivated), it will still be a very efficient filter. It’s been proven to work.

I love plants as a filter just not sold on the gravel. I use it sometimes especially in a pot to keep tall plants upright. Its a necessary evil because every damn time I need to thin the plants I have to pick all that gravel out of the roots and within a year or 2 I'm still without enough to replant. How do all of you thin out plants where the filter feeds the roots so well the plants don't take half the gravel with them. And eventually my compost is full of gravel. MAybe the roots wander through the gravel finding all your pockets of poop for you keeping everything running? I wouldnt trust that deeper than 10 inches though. And still then you need to clean all the gravel out of the roots.

 

[nomadh]

The koi folks i'll call them look at a pond that was a natural pond and it's always the same look at all the sludge all this black garbage. Well to us it looks like mud to the microbes and small invertebrates frogs even its HOME plants love the stuff so who is the sludge bad for the ecology of the pond or the human who see's mud ad mud. Talk to any environmentalist That sludge is where they make there living to them it's hardly mud. They know it's the life blood of aquatic nature. That's why you can't go to one natural pond and not find it. Its mother nature doing her thing.

And dragonfly larvae too. I just keep that in my smaller tub watergardens. My semi tropical fish and paradise fish need a good inch or so down there for winter to keep warm. But its a fine line. If I let it get too deep the pond can turn anaerobic and can kill everything including water lilies.

 

[GBBUDD]

Sorry I have been down the road of the wet dry filter and your spray bar that clogs with algae if not solids in time that too needs to be watched.
Yes anorobic bacteria thrives when it is given all the 02 it needs to devour any ammonia or nitrates but it can begin to touch phosphates along with several other compounds I won't get deep into. All I will say is the plants /mother nature has figured how to deal with these compounds naturaly plants love them . And I have also looked into the aquascape matrix area and there are tunnels trails etc all over the place while the drip is focusing in on only bacteria the bog limits no one. I have found so many bizarre worms bugs and caterpillars in the water that I have never seen before they are clearly aquatic. These will take care of the solids the algae that makes its way to the bog. And while I agree a bog without enough o2 is a lacking opportunity. That is why in my 18 foot. Long bog x 10 feet wide I pump air down to the bottom of the snorkel is this over kill possibly maybe maybe not. All I know is you can pick out a dime 6 feet down on the floor of the pond and easily tell me If it's heads up or down. I have been to the best koi dealers in NY and I am proud to say not one has water as clear as is my pond with the bog. Both these principles have there merits but to me I dispise seeing man made. That's why I have large boulders in my pond and gravel. The muck sludge and what ever tge other terms were to me is HOME for the frogs and countless other aquatic life. Yes my fish occasionally give them selves a good pop in the head or fin as they swam into a rock or got a fin stuck between boulders. WELCOME TO NATURE. To me fish keeping is giving them the best home I can one similar to that of in nature. Yes that includes sludge. "To a degree" I can go weeks without feeding the fish and see they still are growing and fat as the forage throughout the pond.
The trickle filter has its place but to me that's with the contemporary naked liner ponds that have little imagination. It's just not my taste though I have seen many that look great fish are perfect but again not my thing for perfect specimens I would rather a happy home.

 

[GBBUDD]

You have 2.5 ft deep gravel for your water to upflow through as a filter? On the one hand the more media the longer it takes before a problem will show like clogging and channeling. The downside is how much shovelling of gravel and where to put it if there ever is a problem you need to go down there to fix and how do you not destroy the liner doing it? Don't get me wrong if I bought a house with your setup I'm sure I'd love it and use it but I would also have an exit strategy if something ever did go wrong. I'm just a worrier. Or too lazy to accept even a 20+ year maintenance cycle when it comes to shoveling gravel

Hell if your talking shovels you're not half as lazy as I am there's no way in hell at 58 I'm breaking out a shovel to move tones of stone. It's an excavator for me. I can't even back flush the bog and get dirty water to cone out. The snorkel extends up a foot above my bog as an indicator as to if pressure is building up from clogging 4 years latter with a very heavy fish and plant load there's no signs yet.
Trust me I know the trickle well but I feel it is close to days of activated carbon and filter batting. I placed 148 in the Ada competition with my planted tank and mini bog and filter so if there's one thing I can say for certain there is NO ONE way to say you must do this to keep fish . Well other then keep them in water. With the right desires and attitude the time given to your project is what will make it successful. But me I was traveling gone for weeks on end I could not b e there to clean filter pads. The pond is set up to take care of her self with very minimal help from me so far so amazing.

 

[GBBUDD]

And dragonfly larvae too. I just keep that in my smaller tub watergardens. My semi tropical fish and paradise fish need a good inch or so down there for winter to keep warm. But its a fine line. If I let it get too deep the pond can turn anaerobic and can kill everything including water lilies.

I use a pond vac in the spring of will suck up any leaves and sediment b that built up as far as

I love plants as a filter just not sold on the gravel. I use it sometimes especially in a pot to keep tall plants upright. Its a necessary evil because every damn time I need to thin the plants I have to pick all that gravel out of the roots and within a year or 2 I'm still without enough to replant. How do all of you thin out plants where the filter feeds the roots so well the plants don't take half the gravel with them. And eventually my compost is full of gravel. MAybe the roots wander through the gravel finding all your pockets of poop for you keeping everything running? I wouldnt trust that deeper than 10 inches though. And still then you need to clean all the gravel out of the roots.

I agree with 10 inches is not a good number I feel it needs to be deeper to plantsxwith 20 inch deep roots don't clog tge baffles.

 

[brokensword]

No, most of the old timers, 50+year koi members and article authors, have the older style upflow design. [snip] But I still wouldn't WANT to use rock. somewhere inside the filter even then it could start to channel and clog. Without digging it out you'd never know.

Visiting Koiphen and reading what some of these 'old timers' promote, it is definitely NOT upflow wetland filters. There's a decided bias against them, as a matter of fact. IMO, they're gear-driven there and despite success stories, will belittle posts esousing upflow wetland filters.

I would agree re using pea gravel; pieces of plastic with the same surface area would be easier to move/place and do the same job. But we live in a real world and cost is still a factor.

Btw, I am one that did get involved with digging up a bog as I got clogging, but that was due to improper design directions (now rectified in v2) and ignorance of how the plant roots were also contributing to the problem. It wasn't the pea gravel that was a pita, it was the lower layers that would not easily shovel up as they were larger rounded stone. With a cleanout and good flow+pressure, you can backflush and take care of such a problem should it ever arise. No digging up should be necessary.

I still get a good amount of skepticism from your replies. Makes me want to ask how you attribute the may success stories of people here that use such systems, and the vast majority do not add air to their bog, they also more often than not, shut their bogs down for months at a time and do not have dying fish when started back up. As long as the pond water being pumped into the bog has adequate O2, how can there be a problem? The fish will die a lot sooner with such a lack than the bacteria will. And though bacteria in the bog doesn't completely die off, it certainly ebbs and flow re life cycle depending on the nutrient levels.

And lava rock, while good for a Bakki shower, is not as good in a bog; there's MORE surface area for bacteria colonization with the same volume of pea gravel. It's also a lot harder to clean, should you ever need to, be it by hand and hose (like I had to) or backflushing with a pump.

In all this, I think if you consider that those that use upflow wetland filteration (even SMALL versions like @addy1 and @mrsclem using planter bogs to filter) can boast healthy ponds with very clear water, to go with the VERY LITTLE EFFORT to maintian, any counter arguments seem frivolous or biased. There's more than one way to build a bog filter and within this is the fact there's a lot of successful leeway re parameters. That all by itself should say something.

 

[combatwombat]

NO ONE way to say you must do this to keep fish . Well other then keep them in water.

Damn! Science is so close to solving that pesky problem!

 

[nomadh]

I got to admit you all have shifted my thinking somewhat. If I had tons of space I could see it but I'd still prefer a lighter easier to move media. And I know upflows can work, with enough space. My first pond was 20 years ago. And my first filters were a complete guess. And horrible failures. So I tend to factor in the rebuilding work. I am very very thankful I didnt use any rock those times
I'm a waterlily guy so if I have room for a big gravel bog it means I got room for another pond for small fish and waterlillies and a small trickle tower filter instead.

 

[GBBUDD]

Rock you say you feel it's the root of all evil in the pond from what I'm reading . If this is evil I'll take it all day

Going for it! phase one 12,000 gallon pond.

Just love your pond, it is beautiful!

www.gardenpondforum.com

Sorry the links not working from my phone go to the video on the 3oth on that page above

 

[addy1]

You have 2.5 ft deep gravel for your water to upflow through as a filter? On the one hand the more media the longer it takes before a problem will show like clogging and channeling

It has been running 10 years, no sign of channeling. I have a bottom drain for the bog, turned it on once, nothing but clean water came out, never did it again.
I do draw the water from about a foot from the bottom of the pond, external pump, have a 5 gallon bucket over the water intake to keep the draw in any one place down. Before I did that I sucked in a lot of fry.
Turn it off every fall, back on in the spring, never a issue.