Sissy 2 of you'd postds in this thread lead me to believe you don't understand how this filter works. The water is pulled downtthrough the gravel, so all the debris stays in the pond. If the pump dies, it all floats back up.
Under gravel filtration and air diffusers?
- Thread starter The Pondster
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Everything we know about koi and have read about them in the last 27 years says that undergravel filtered ponds whilst a way of filtering ponds are time consuming and need to be very carefully cleaned , so you will be creating alot of work for yourself believe me I know
"For 22 years of our 27 years we kept koi indoors in a huge indoor setup holding 1 ton or 220 gallons of water for a while we had undergravel filtration but scrapped that idea as being a pain to clean even with a filter converted into a vacuum".
Upscale this your still going to have the same problem as koi by their very nature are prodigous makers of detritus, this gets into the gravel and much is converted by helpful bacteria, however if not cleaned thuroughly and I mean thuroughly you cant help but create pockets of deritus which can harbour a nasty form of bacteria "gram negative bacteria", which can remain inactive until disturbed.
This nasty form of bacteria can and will cause your koi major problems which if not recognised in time can claim the lives of your koi.a swab must be taken and sent to a vet to asscertain which bacteria it is and a prescription made for the correct antibiotic , "all this takes time thus you loosing more fish during this waiting period".
The pipework underneath can also become blocked over time, so you can imagine what will happen to your pond then
Just because your friend has lots of bonsia and is Japanese dosent mean he cant have problems with his pond through the use of undergravel filtration.
Many of the more modern books on koi advise against this form of filtration for the reasons weve given.
You'd find it less time consuming and far cleaner and healthier to install a bottom drain in your pond running to a vortex via a 4" pipe buried under the pond when its constructed adding a 4" slide valve just prior to your vortex a multi bay filter is added after your vortex ( the vortex sometimes comes as part of the multibay package ), our own are seperate filters running in sequence.
The detritus is removed from your pond into the vortex where the large bits settle which can be drained weekly, fortnightly or monthly through a 2" slide valve at its base, which you choose thats up to you, we choose to do it weekly.
The multi bay filtration then removes the smaller bits that dont get to settle and with friendly bacteria in all the bays by the time it comes back into the pond the water is healthy and crystal clear, each bay also has a small 2" slide valve the same as the vortex.
You connect all these 2" slide valves to a pipe that takes this waste water direct to your drain.
A plus to this method is that you have to add more water to the pond, thus doing a water change, every time you drain the vortex to clear it of detritus you must also purge your bottom drain I do this twice giving me aproximately a good water change of around 40% of the ponds volume of water
I note John also agree's about the undergravel system having had its day in the spotlight :-
So between us I hope we can change your mind about installing oneUnder-gravel filtration was touted as THE system for ponds, back in the late 50's and early 60's. When the pond went out for a few hours, people would lose all their fish! It seems once the water stops moving, the whole thing turns into a SEPTIC TANK! These systems are not used today for that very reason!! BTW, I knew one pet shop owner who was away at a convention when he got an urgent phone call saying that his large air pump was no longer working and that he had several dead fish. By the time he got there, he had lost every fish in the tanks serviced by that pump. All were fitted with undregravel filters! He used to swear by them.... now he swears AT them!!
John
Dave
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sissy
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your assuming the pump dies .Mu water goes in the top of my filter and bogs by what I have seen built by some water comes in through the bottom and out the top and I have seen 2 of them where they have the water coming in from close to the top where the plants are .I never under stood bogs and don't pretend to and not sure how you clean one .That is why I stay with my filter tanks with plants in them .I have a small pump in the bottom of each tank and I plug it in and run hose into a bucket or the lawn from the pump and then I am done .i unplug the pump and do a small water change out in my pond .I find this way is much easier than a clean out tap at the bottom since my tanks are set inside liners so any spill over goes back in the pond .Why does addy's work so well and others have luck with them .I have even thought of taking my 1 tank out and building the front up of the liner and making it just for plants .Even pond digger did a small patio pond with a bog filter
Sissy do you understand this is not a bog? It's in the pond. Also, the pump will go out at some point. For example last week I was without power for 24 hours. Pump was off.
Sissy as diesilplower has said this is at the bottom of the pond not a bog filter they are old school from the early days of koi keeping and proven not to work well koi keeping books nowadays suggest against this form of filtration
Dave
It may not be a "bog" but it works the same way. It's rocks or gravel and water flows through them, and hopefully the rocks or gravel build up a good bio-film of aerobic bacteria and they do their thing. It's not rocket science.
Some people use lava rocks in tubs or barrels as bio-media for the water to flow through, many people discourage the use lava rock because it's heavy and hard to move around and deal with when it comes time to clean out the barrels or tubs. That being true, then how much harder is it to clean the rocks on the bottom of a pond, or in a bog? Both will eventually collect enough sediment that one day need they'll need cleaning. Just how long you can put that off depends on the size of bog or the amount of rock or gravel on the bottom of your pond, how much debris or fish poop in your pond, and just how long you'll be willing to put it off. No filter I know of has an exact time it needs to be cleaned, we usually just set a routine, or do it sometime after it looks like it needs cleaning. I'm thinking everyone has, at one time or another, let their filters go past the time they probably should have cleaned them. The thing with bogs or under gravel filters is it's really hard to tell exactly just how much stuff they may have collected in there, so it's really hard to judge when they might need cleaning. It won't happen all at once, there will be areas that collect more debris then others, and once enough stuff collects in one place the water will start channeling. or "short circuiting", and when you get pocket of debris where the water doesn't flow at all then the oxygen can't get to it and it will become septic, meaning anaerobic bacteria start to thrive and consume the organic waste in those pockets. You won't know it's happening because it will be deep in there somewhere. The older the bog, or under gravel filter gets, the more stuff will accumulate and the more pockets of anaerobic bacteria you'll get. It's not the end of the world, but it's not an ideal thing. It's not uncommon to get pockets of anaerobic bacteria in the bottom of plant pots, but do you really want anaerobic bacteria growing in what is suppose to be your filter system.
Admittedly I get the same thing in the bottom of my settlement tank if I leave it for a long time without draining it. The debris accumulates at the bottom of the cone shaped tank and after it gets a few inches thick the bottom portion that is buried doesn't get any oxygen anymore and starts to turn septic. Sometimes it can take less than a month, but boy does it stink when I drain it off. But here's the thing, to get rid of it all I have to do is open a valve and the water pressure forces it out the bottom drain and into a waiting bucket. Done! Not quite so easy to get rid of anaerobic muck buried under rocks or gravel.
Some people use lava rocks in tubs or barrels as bio-media for the water to flow through, many people discourage the use lava rock because it's heavy and hard to move around and deal with when it comes time to clean out the barrels or tubs. That being true, then how much harder is it to clean the rocks on the bottom of a pond, or in a bog? Both will eventually collect enough sediment that one day need they'll need cleaning. Just how long you can put that off depends on the size of bog or the amount of rock or gravel on the bottom of your pond, how much debris or fish poop in your pond, and just how long you'll be willing to put it off. No filter I know of has an exact time it needs to be cleaned, we usually just set a routine, or do it sometime after it looks like it needs cleaning. I'm thinking everyone has, at one time or another, let their filters go past the time they probably should have cleaned them. The thing with bogs or under gravel filters is it's really hard to tell exactly just how much stuff they may have collected in there, so it's really hard to judge when they might need cleaning. It won't happen all at once, there will be areas that collect more debris then others, and once enough stuff collects in one place the water will start channeling. or "short circuiting", and when you get pocket of debris where the water doesn't flow at all then the oxygen can't get to it and it will become septic, meaning anaerobic bacteria start to thrive and consume the organic waste in those pockets. You won't know it's happening because it will be deep in there somewhere. The older the bog, or under gravel filter gets, the more stuff will accumulate and the more pockets of anaerobic bacteria you'll get. It's not the end of the world, but it's not an ideal thing. It's not uncommon to get pockets of anaerobic bacteria in the bottom of plant pots, but do you really want anaerobic bacteria growing in what is suppose to be your filter system.
Admittedly I get the same thing in the bottom of my settlement tank if I leave it for a long time without draining it. The debris accumulates at the bottom of the cone shaped tank and after it gets a few inches thick the bottom portion that is buried doesn't get any oxygen anymore and starts to turn septic. Sometimes it can take less than a month, but boy does it stink when I drain it off. But here's the thing, to get rid of it all I have to do is open a valve and the water pressure forces it out the bottom drain and into a waiting bucket. Done! Not quite so easy to get rid of anaerobic muck buried under rocks or gravel.
Here is a video of the pond I mentioned:
and another: As you can see some huge fish that have been there for many years and clear water.
and another: As you can see some huge fish that have been there for many years and clear water.
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They perform perfectly installed correctly that is
j.w
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There seems to be two methods of under gravel that may work and they are at totally opposite ends of the spectrum.
1. the natural swim pond by air and venturi tubes. these pull water down through the gravel. now the key seems to be 100% of the surface area of the pond is equal to the wetland section if not 200% of the surface area. this first video while it looks nice in the video i know failed down the road only a couple years latter i belive because his ratio was like 50%
while ponds like the second link though this one is new seem to work given time.
this one is an upflow not undergravel
1. the natural swim pond by air and venturi tubes. these pull water down through the gravel. now the key seems to be 100% of the surface area of the pond is equal to the wetland section if not 200% of the surface area. this first video while it looks nice in the video i know failed down the road only a couple years latter i belive because his ratio was like 50%
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I have built many under gravel grid suction systems and have eliminated any muck and clean outs . I have a video on YouTube that is an airlift grid .
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Installed correctly they work beautifully
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