Rebuilding a pond, tips on bog filter?

[dinm]

I currently have 900 gal pond, 3 Koi that are I think now in between medium/small size and 8-9 goldfish. The Koi decision was not the wisest I suppose, but they've grown on me and they seem far more quirky and nosy than goldfish, extremely curious.

I had a leak though, so instead of rebuilding next spring I'm just gonna do it now. I am gonna end up expanding to about 1300 gal, probably ends up less because I don't want it to be as deep and will have shelves, so that should help with the fish load.

Not part of my original plan, but it seems it is the perfect time to buy a 200g barrel and make a bog filter out of it, and I can grow plants in it as well so another benefit. I'd bury the barrel and have it spill into the pond.

As for overlayment, I ordered 7oz for underlayment, 5oz for overlayment, for use with rocks. I was not able to find black geotextile that was tougher than that, there was I think 10oz,17oz gray geotextile, but I thought it'd be hell to hide that, though I might order 300g geotextile it to use where necessary and black 5oz geo on top of that.

 

[GBBUDD]

1300 GALLONS is pushing it for 3 koi and 8 gold fish , 900 is a crime. those koi will continue to grow and as they do the amount of waste that they produce is amazing a rdf with a bead filter would be needed

 

[Lisak1]

I'm with @GBBUDD - you need to really ramp up your filtration for that many fish. A bog filter will help, but your water volume is still very low for that bio load. If you can increase the size of the bog, that will also help as that increases your total water volume. And I would build deeper if you can. Another way to increase water volume that isn't often discussed is underground - if you don't have room for more pond, maybe you have room for a rain exchange. You can put patio or grass right over it and lose no landscape area but increase pond volume exponentially.

Just a few ideas! Good luck to you! Post your rebuild details - we love to watch other people work!

 

[netvine]

300 gallon stock tanks are an economical alternative to barrels and fairly easy to plumb for bog filters.

 

[dinm]

I'm with @GBBUDD - you need to really ramp up your filtration for that many fish. A bog filter will help, but your water volume is still very low for that bio load. If you can increase the size of the bog, that will also help as that increases your total water volume. And I would build deeper if you can. Another way to increase water volume that isn't often discussed is underground - if you don't have room for more pond, maybe you have room for a rain exchange. You can put patio or grass right over it and lose no landscape area but increase pond volume exponentially.

Just a few ideas! Good luck to you! Post your rebuild details - we love to watch other people work!

Liner calculator sites say I would have enough for the pond to be 10x10 feet and 3 feet deep, and that would end up at about 2000 gal, and I think up to 2500 gal if I end up deeper/wider, but with shelves I will end up losing some of that. Liner is 20x23. So then I guess I would aim to have shallow shelves for marginals and one deeper. The pond shape is rectangular though.

It seems I'm gonna need a whole lot more rocks though.

I am gonna be digging it out on Monday and setting the underlayment, should be receiving the liner on Tuesday.

 

[GBBUDD]

Depending on your soils 3 foot is a good depth without worrying to badly regarding collapsing. Deeper than that does require larger rocks above what one man can maneuver. Plus 3 feet is easier to maintain . Deep enough to get away from predator's. I would start with gold fish get familiar with your set up then think about koi in a few years

 

[dinm]

Removed the liner today, was digging for 4 straight hours. Don't even have rocky soil, but heavy clay, and was very moist so it didn't help. I removed quite a lot of gravel from the pond, it was amazing how much there was in it, at the bottom there was probably 6-7 cm of it and that is still being conservative, and I was the one adding all that rocks, and it still surprised me. I curse gravel or any kind of small rock now.

I was told by someone here that Chameleon plant is quite invasive, and they were not wrong, it was reaching I think almost to the bottom of the pond, that's how big its root was, I like it though.

I still have time to make it better but it seems it will end up at 1400g , though its not really an accurate measure, I'm just guessing by the main part, the 3ft deep one, which is at about 1000g now and it will get bigger by the end of it. I have 3 sides with shelves, 1 side has no upper shelf just one that is 24". And then with all these shelves and whatnot is will I have even enough liner. The deepest part is 3.3ft, then there are two shelves at 24", and then the upper ones which are for marginals.

The one side with no shallow shelf I thought about placing bigger rocks and using some pea gravel in between so I can plant in between, but that's just a work in progress, I still hope to reach at least 1600g one way or another. Just to be better for these curious Koi.

The 3ft part I am honestly not even sure whether to use rocks there, the rocks I have all very dark color which is gonna look amazing, I think even if I didn't do the bottom it would still look quite good. Would post a picture of how it currently looks but didn't get a chance and it's dark now.

 

[dinm]

I've set the underlayment, liner and overlayment today. No idea whether to rock the 3ft part, seems I would require a great deal of rock and it may be better to just do the shelves?

 

[GBBUDD]

Unfortunately there is no wrong answer just keep in mind at some point someone will be in there and you want to make sure nothing is going to collapse and hold them under

 

[dinm]

Just cleaning up now, rained today and filled a little bit of the pond yesterday, never a bad thing. Now is left to stack the rocks properly so that if I walk on the shelf I don't end up breaking my feet, or falling in the deep part. So much rock now that I'll never use, perhaps for the better, gravel now I will spread over the paths in the yard.

Still warm for some reason, in November.

I am also wondering, I have some parts of the pond that are perfect for a small skimmer, is there anything special about a skimmer other than its a pump pulling in water and debris into it?

 

[GBBUDD]

If you want to make a small skimmer in a still corner. If a pumpnis to large you can always use a intake hose from a external pump

 

[dinm]

Still cleaning up, got some more rocks today so will be completing shelves tomorrow. Decided against filling the deeper part today, gets dark early now so I figure I'll just clean up all the rocks etc tomorrow and put them in when everything's ready.

Starting to look good, I only have one shelf left. I've wanted to make some rock steps so I can walk in the pond though easily. Most rocks I've interlocked and started filling in gravel so its really nicely locked up. Fortunately the shelves are wide.

I've also planted in between the rocks, so plants cannot move, which is easier than dealing with it later and looks really nice.

 

[GBBUDD]

i'd think about locking the stairs in with some mortar

 

[dinm]

i'd think about locking the stairs in with some mortar

They are not really proper stairs, just stepping stones I guess you'd call them, they seem very stable, rocks that are sort of flat so walking on them is safe.

Not much left to do now, just putting the last two big rocks in one corner and turning on the water, then trimming the liner and cleaning up. Thank God the shelves are wide, if they were not these rocks would be tumbling down so easily, should have made them wider.

Looks really good, will post some pics later before and after.

 

[dinm]

Finished putting in the stones. Water put in as well, and fish. Now is the question of safety for kids, and that is a tricky one. Not my kids of course, I don't have any, but family. And kids go everywhere, they just don't care, and the parents, well they don't seem to care either, until something happens that is. So I will have to look for some ways at least to slow down their movements etc, probably with boulders. Only two sides of the pond are really accessible for them, so it narrows it down.

Iffy question I guess, something I must think of unless I want to worry about it.