The Accidental Pond - filter problem


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Well not quite accidental. I did intend to build a pond when I first put the spade in the ground. A nice small, manageable pond, natural, un filtered, about the size of a bath tub...

What happened next is a blur, hazy memories of being 6 ft down, ordering breeze blocks and thinking about filters and koi :dunno:
And that was as far as I got. A large deep breeze blocked sided hole.

A few years past and covid arrived. With plenty of time on my hands I decided to finally finish it. Scale it down I thought. Can't be bothered with filters and messing about. Fill a lot of it in and go back to a larger version of the original plan.....
Of course that didn't happen. I have finished the pond though, and I'm halfway through the waterfall I added :whistle:

I intended to make my own multi bay filter from an old loft tank. For this purpose I built a space next to the pond at pond level, a sort of filter hole. The idea was to have the 2 bottom drains connected directly to the filter then pull the water through from the other side with a variable pump then back into the pond via a uvc. Essentially the filter would be a connected mini pond sharing the water level with the main pond. I have no idea if this is a standard thing, I just dreamed it up and it felt like it would be an efficient and zen like solution. Also this way everything would be nicely hidden under a decking lid which would double as a viewing platform. I really don't want to be able to see the technical bits and I don't have a big enough garden to hid it any other way.

Planning clearly not being a religion I follow devoutly I used the 'that'll be big enough' system of measurement. And it was, exactly big enough to fit in the filter hole leaving zero room for the in and out plumbing etc :unsure:.
So
Plan B, buy a new, slightly smaller, container. Turns out more expensive than buying a box filter.
Plan C, buy a box filter. None of them work in a way that I can adapt for my sunken filter bay.
Plan D, buy a Yamitsu KF 4000 and adapt it to work like my original plan. Maybe.
Plan E, buy a large capacity pressurised filter. I've finally got around to doing a bit of research and it seems that 'proper' pond owners don't rate them.
Plan F give up on hiding the filter. Not really what I want to do. Apart from the aesthetics it would leave me with a large empty hole in the ground that could have been more pond.That said the nexus range are impressive, especially the self cleaning ones. But ugly, so ugly....
Plan G do what I should have done in the beginning and join a forum to get feedback and advice from wiser more knowledgeable folk......

Few pond facts to help with context
3.5m x 3m not square, 6ft at deepest point, many shelves, shallow areas. Approx 4250L based on flow rate and time to fill. Waterfall runs on a separate pump to future filter system although I have added a small single cloverleaf VH2 at the top (buried and behind rocks) which is fed by a feed from the main waterfall supply and outlets back into the top. The waterfall has (will have) 3 tears and 2 are large enough to take 2 or 3 bags of gravel. I assume this will give me some additional biological filtration.

I will not be getting koi. It currently has 11 small (1.5" - 3") gold fish. I intend to add maybe 5 more and a handful of shubunkins. I've seen you can buy UK native fish such as tench, minnow, rudd etc which I'm interested in doing at some point if suitable. I have various plants in already inc bullrush, lilys, floating plants and aerators. I want to add more and cover maybe 50 - 60% of the surface to help with water clarity etc

I'm in the UK
 
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addy1

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Welcome to our forum!

What a journey! Build a bog filter, you will never regret it!

 
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A lot of us don't have commercially bought filters. We use a bog filter.
Maybe you can expand your filter hole to use as a bog.
It's basically a 12" deep hole with a pond liner that has pvc pipes laid in there. The pipes have a bunch of slits cut in them. Then that is covered with pea gravel. The water is pumped from the pond, through the slits in the pipes, rises up through the gravel and returns to the pond via gravity. Plants are grown directly in the gravel. The plants thrive on the nutrients in the water. So, it's two fold. The gravel and the plants clean the water.
The bog surface area should be 30% of the pond's surface area.
This is the best filtration in my opinion. My water has never been so clear. It looks like you can drink it. I wasted so much time and so much money on filters and UV lights over the years.
There are several threads on pond bogs here. Do a search and read up for more details on how to build one.
 
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Hey @Dirty welcome to the very helpful forum.

As already mentioned, build yourself a bog filter if you can since it a natural way of cleaning and filtering your water as well as allowing you to grow plants so it's all like hidden.

It's something I wished to do on my raised pond setup when UK weather permits it and I can find a suitable container.

Just think, no UV or pressured filter to clean out when full of muck and it's all done el-natural :)
 
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Hello and welcome! Wow, I didn’t know when to stop reading your spaced out post, LOL!
First off, sorry about that. I copy and pasted it from 'notes' and didn't realise it turned 1 space into 4. Ouch. Can't even edit it now sorry.


Secondly wow. Straight in with a resounding full house for option H. It's food for thought. There's not a lot of space. Certainly not 30%. The waterfall pump and pipes are an unmovable fixture but...., but.... something could be done maybe...... This is brilliant. Thank you. I'll have a ruminate and get back to you.
 

addy1

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First off, sorry about that. I copy and pasted it from 'notes' and didn't realise it turned 1 space into 4. Ouch. Can't even edit it now sorry.
fixed!
 
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Once again thanks. No I mean it, thank you, great suggestion.. I've been thinking a lot about a bog filter now thanks to you all. Its something I'd love to do. I estimate my ponds surface area is approx 6 sq M and at most I think I can squeeze in just over 1 sq M of bog filter so? ........

but should I be asking questions here or in 'the thread'
 
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A bog can be any shape you like. If you don't have room on one end, you can make a long narrow one along the side of the pond. Or two long narrow ones, one on each side. 12" or 18" wide and along the whole length of the pond. With plants growing in there, no one would even know a bog filter is even there.

I know, I know...we keep pushing this bog thing, but for good reason. They simply work if sized and built correctly. No more rinsing filter pads. No more expensive inadequate filters. Just clear water. I've never enjoyed my pond so much since adding the bog this Spring. Two months of clear water, like never before. I can see every tiny fry swimming around. I wasted so much money and time cleaning out filters over the years.
 
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A bog can be any shape you like. If you don't have room on one end, you can make a long narrow one along the side of the pond. Or two long narrow ones, one on each side. 12" or 18" wide and along the whole length of the pond. With plants growing in there, no one would even know a bog filter is even there.

I know, I know...we keep pushing this bog thing, but for good reason. They simply work if sized and built correctly. No more rinsing filter pads. No more expensive inadequate filters. Just clear water. I've never enjoyed my pond so much since adding the bog this Spring. Two months of clear water, like never before. I can see every tiny fry swimming around. I wasted so much money and time cleaning out filters over the years.
I have a small suburban garden and I'm pretty stuck as to where I can fit one in. Space wise I could put one elsewhere but running the electrics would be problematic. As it is the space I intended for filtration is right next to the shed so plugging in is easy.

I've read that it should be 30% of the area of the pond but would a deeper bog filter mitigate the lack of available space? I could probably go to around 800mm deep.

Also what about larger debris. Do people have some form of mechanical filter/mesh/grid pre bog?

Some pics










 
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Nice pond! Thanks for the pictures!

What about all that space in the foreground of the last picture? The end where the pond is wider. There looks to be plenty of space for a bog.

Some here have gone deeper where they didn't have the space. I can't vouch for that, so hopefully they will see this and chime in.
 

addy1

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Mine is deep and large, deep works.

As far as large debris, pull your water about a foot off the bottom. That is what I do. I have a leaf basket before my pump (external) but never need to empty it all summer. My bog gets mainly dirty but debris free water.
 
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Nice pond! Thanks for the pictures!

What about all that space in the foreground of the last picture? The end where the pond is wider. There looks to be plenty of space for a bog.

Some here have gone deeper where they didn't have the space. I can't vouch for that, so hopefully they will see this and chime in.
Thank you.

Yes you are right, there is space at the other end but it would be a job to run electricity there. I have power in the shed already so it's a simple task to put an extra pump in close by. The garden is on a higher level to the house and there is a concrete wall and concrete steps. Any power supply to the rear of the garden would have to run between the pond and the fence then under the waterfall. Not impossible true but not really what I want to either do or use that space for. I was going to grass it over and have it for sitting and enjoying the pond.

You have given me an idea though. I have a supply for the waterfall and vortex already. I could maybe put another small/shallow bog at the top of the water fall to the right and gravity feed it back in..........
 
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Mine is deep and large, deep works.

As far as large debris, pull your water about a foot off the bottom. That is what I do. I have a leaf basket before my pump (external) but never need to empty it all summer. My bog gets mainly dirty but debris free water.
Great thanks.

I have 2 bottom drains already installed. I'll have to have a leaf basket.

I have a question about the pipework with slits cut in. I understand this would distribute the pond water evenly over the bog, but doesn't that also mean that the water that exits nearest the outflow will get the least treatment? Do some bog filters have water simply dumped in one end and flowing out the other (also potentially with a system of internal barriers to ensure all areas get roughly equal flow)? Pro's, cons?
 
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Great thanks.

I have 2 bottom drains already installed. I'll have to have a leaf basket.

I have a question about the pipework with slits cut in. I understand this would distribute the pond water evenly over the bog, but doesn't that also mean that the water that exits nearest the outflow will get the least treatment? Do some bog filters have water simply dumped in one end and flowing out the other (also potentially with a system of internal barriers to ensure all areas get roughly equal flow)? Pro's, cons?

You could always cut thinner slits closest to the water entry and make the other slits middle to other side larger, that way water is some ways distributes evenly...if that makes sense.
 
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As far as electricity all the way back there, you don't need any. The bog doesn't need electricity. Your pump sends the pond water to the bog and the water flows back to the pond via gravity. The bog is higher than the pond. How much higher is up to you. It can be just a little higher, built partially above ground or a lot higher built completely above ground.

To me, that spot back there is perfect.

Due to the force of your pump, the water in the slit pipes will spread evenly. The water will hit a dead end at the end of the pipe and will get forced through the slits.
 
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Mine is 26ish feet long, the slits near the pumps are further apart then the slits at the far end of the bog. It is working great.
You don't need power, like @poconojoe says, to run your bog, just a pump , a T off your existing pump or a new pump and just run the lines to the bog.
 

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