Bogged down by bog technicalities.

[LuckyDog]

Hi all,

I'm supposedly making a bog filter in a box for my "patio pond." Progress is pretty slow, mainly because I'm frozen by uncertainties and lack of DIY skills. Anyway, I've got a horribly expensive 190 liter box, semi sunk in the ground slightly above and behind my pond. Because of the way my space is there's no room for error with regard to the water exit (for eg if there was a problem in the middle of the night). The inlet hose is 19mm (3/4") do you think an outlet pipe of 40mm (1.5") is sufficient? Should I put a 2nd outlet 'just in case"? As it is, the 1st outlet will be only 2 or 3" from the top of the box. Right now we have a severe shortage of medium sized Uniseals in the UK, so I'm going for a Solvent Weld tank fitting and matching pipe.
So that's one query, another is that now my box is in situ and can't be moved, I'm worried about drilling out the hole! Thinking I'm having to brace it with a piece of wood to TRY and stop the box splitting. It all seemed like a good idea at the time!

 

[brokensword]

Hi all,

I'm supposedly making a bog filter in a box for my "patio pond." Progress is pretty slow, mainly because I'm frozen by uncertainties and lack of DIY skills. Anyway, I've got a horribly expensive 190 liter box, semi sunk in the ground slightly above and behind my pond. Because of the way my space is there's no room for error with regard to the water exit (for eg if there was a problem in the middle of the night). The inlet hose is 19mm (3/4") do you think an outlet pipe of 40mm (1.5") is sufficient? Should I put a 2nd outlet 'just in case"? As it is, the 1st outlet will be only 2 or 3" from the top of the box. Right now we have a severe shortage of medium sized Uniseals in the UK, so I'm going for a Solvent Weld tank fitting and matching pipe.
So that's one query, another is that now my box is in situ and can't be moved, I'm worried about drilling out the hole! Thinking I'm having to brace it with a piece of wood to TRY and stop the box splitting. It all seemed like a good idea at the time!

the general rule is the outlet is twice the diameter of the inlet, but of course, you can always add another or make the one outlet even larger. You could also consider making a weir/blade for your outlet to give you a sheeting action waterfall.

What is this box made of? Some sort of plastic? Do you have a hole saw attachment for a drill? If plastic, make the drill speed just fast enough to not tear the plastic up while slow enough to almost melt the circle, which would keep any cracks from happening.

To make sure any spillage/overage from my bog stays in the bog/pond, I have one liner for the whole system. If you have only a box and an outlet pipe, consider some way of encapsulating the bog box and creating a 'baggie effect' that would catch and return the water to the pond (as in my own example). That is, I like to have ALL my plumbing and water paths lined. The only way I'll lose water is if one edge gets pushed down or a tear happens below the waterline. All 3 of my waterfalls are protected this way by one underlying liner that dumps back into the pond.

If you have any pics, it would help insure any advice given is correct. I'm trying to visualize without a lot of detail, here.

Good Luck!

 

[LuckyDog]

Good morning, Broken Sword, and thank you so much for getting back to me.
The box is a Heissner water reservoir for features etc, 190 liters capacity (about 1/4 size of the actual pond but I'm hoping to at least double up the pond size next summer). The box is plastic and has a little flex.
Posting a picture or two; as you can see, the location isn't suitable for an all encompassing liner, unfortunately.
I've cut a hole in the grid at the bottom, a piece of gutter down pipe fits in the hole (with cutouts at its base to allow water flow) and my hand held and operated pump fits in nicely to remove water from underneath the grid. - digressing here to show there is a little method in my madness - Anyway, with the gap between box and pond the water back to the pond will always have to pass through a pipe of some sort. Fanciful maybe, but I'm wondering about fitting the half size guttering that's sold for sheds ect. around the edge of the box, once it has a wooden surround. I guess the ultimate fail-safe is that my pump is sitting on a brick and the pump would die before the entire pond emptied.
I don't yet have a hole saw, waiting until an actual bulkhead is here before committing to buying one.
I'm thinking of putting an inch or two of slate cobbles on the grid to prevent the smaller clay balls I've already bought falling into the void. The clay balls seemed a good option for me as they're relatively light, I'm an old gal now and things aren't as easy to hump around as they used to be!
Apologies for the scruffy look of things, all a work in progress.

 

[yorkshire pudding]

hi lucky dog,

this is quite similar to what you have i had two outlets, but in the end i added a third as the flow was getting near the top, hope this helps. cheers mark

 

[Lisak1]

From the photos is appears your bog box is below the level of the pond? Is that correct? I'd raise the bog above the pond, like you see in @yorkshire pudding 's photo... but maybe it's just the angle of the camera now that I look again!

 

[LuckyDog]

From the photos is appears your bog box is below the level of the pond? Is that correct? I'd raise the bog above the pond, like you see in @yorkshire pudding 's photo... but maybe it's just the angle of the camera now that I look again!

Hi Lisak,
No, don't worry, the bottom of the box is just a few inches below the topmost capacity the pond, while the top of this somewhat deep box is above the pond. I'm not surprised I've caused some confusion because my camera skills are not much better than my DIY skills

 

[LuckyDog]

hi lucky dog,View attachment 143130this is quite similar to what you have i had two outlets, but in the end i added a third as the flow was getting near the top, hope this helps. cheers mark

Hi Mark and thanks for your reply. Your box looks almost identical to mine, what capacity is it? Are the outlet pipes 40mm? It's scary to think that the two together weren't enough to keep the level reasonable. My pump is said to shift "up to" 2000 liters per hour, I suppose it could get close to that when I remove the internal filters. However, I'm going to divert half the water away from the box.
Your system looks great, have you a picture of it filled and operational? I would love to see more.

 

[Dimelius]

Hi all,

I'm supposedly making a bog filter in a box for my "patio pond." Progress is pretty slow, mainly because I'm frozen by uncertainties and lack of DIY skills. Anyway, I've got a horribly expensive 190 liter box, semi sunk in the ground slightly above and behind my pond. Because of the way my space is there's no room for error with regard to the water exit (for eg if there was a problem in the middle of the night). The inlet hose is 19mm (3/4") do you think an outlet pipe of 40mm (1.5") is sufficient? Should I put a 2nd outlet 'just in case"? As it is, the 1st outlet will be only 2 or 3" from the top of the box. Right now we have a severe shortage of medium sized Uniseals in the UK, so I'm going for a Solvent Weld tank fitting and matching pipe.
So that's one query, another is that now my box is in situ and can't be moved, I'm worried about drilling out the hole! Thinking I'm having to brace it with a piece of wood to TRY and stop the box splitting. It all seemed like a good idea at the time!

I'm a newbie, but in my opinion one more is better that one less...and anyway at end you can camouflage all the pipes that come out.
For drilling i used a cutter for glass with diamond(italian example: https://www.amazon.it/Diamantate-Pr...ocphy=1008855&hvtargid=pla-814779267961&psc=1) and got no problems with plastic coz is making a clean work not like wood cutter with that "huge" teeth.
For Bog costruction there is a sticky post in DIY forum

 

[LuckyDog]

I'm a newbie, but in my opinion one more is better that one less...and anyway at end you can camouflage all the pipes that come out.
For drilling i used a cutter for glass with diamond(italian example: https://www.amazon.it/Diamantate-Pr...ocphy=1008855&hvtargid=pla-814779267961&psc=1) and got no problems with plastic coz is making a clean work not like wood cutter with that "huge" teeth.
For Bog costruction there is a sticky post in DIY forum

Thanks for that. I'd never thought to look at glass cutting disks, but you're right - those wood saw cutters look very fierce! Incidentally, did you back the plastic you cut with wood or something (to brace it?/ As for outlet pipes, yes, I've now been convinced to at least double up, thanks to the great advice offered on the forum.

 

[Dimelius]

No, i didn't, but prolly work well with that too...and these cutters will "melt" the plastic and don't crack it.

 

[brokensword]

Good morning, Broken Sword, and thank you so much for getting back to me.
The box is a Heissner water reservoir for features etc, 190 liters capacity (about 1/4 size of the actual pond but I'm hoping to at least double up the pond size next summer). The box is plastic and has a little flex.
Posting a picture or two; as you can see, the location isn't suitable for an all encompassing liner, unfortunately.
I've cut a hole in the grid at the bottom, a piece of gutter down pipe fits in the hole (with cutouts at its base to allow water flow) and my hand held and operated pump fits in nicely to remove water from underneath the grid. - digressing here to show there is a little method in my madness - Anyway, with the gap between box and pond the water back to the pond will always have to pass through a pipe of some sort. Fanciful maybe, but I'm wondering about fitting the half size guttering that's sold for sheds ect. around the edge of the box, once it has a wooden surround. I guess the ultimate fail-safe is that my pump is sitting on a brick and the pump would die before the entire pond emptied.
I don't yet have a hole saw, waiting until an actual bulkhead is here before committing to buying one.
I'm thinking of putting an inch or two of slate cobbles on the grid to prevent the smaller clay balls I've already bought falling into the void. The clay balls seemed a good option for me as they're relatively light, I'm an old gal now and things aren't as easy to hump around as they used to be!
Apologies for the scruffy look of things, all a work in progress.

Others have followed up and given good advice. One thing I WILL note though is this; when we make our bogs, we like to keep a 6" wall that is higher than the bog water outlet level. This is because over time, as the plant roots fill in, as the pea stone gets a bit clogged, the water level will rise and if you don't have enough area for outpour, it'll rise high enough to flow over the side of the bog. So, keep the outlet of your bog lower than the top to help with this. If you DO see issues over time and fear an overpouring, just start adding more outlet pipes.

Btw, I'm not clear with your statement re the pump; you SHOULD be pushing water from your pond to the bottom of your bog, NOT pulling it using a pump at the bottom of the bog box. If you're using this pump only as a cleanout option down the road, disregard that last.

 

[yorkshire pudding]

Hi Mark and thanks for your reply. Your box looks almost identical to mine, what capacity is it? Are the outlet pipes 40mm? It's scary to think that the two together weren't enough to keep the level reasonable. My pump is said to shift "up to" 2000 liters per hour, I suppose it could get close to that when I remove the internal filters. However, I'm going to divert half the water away from the box.
Your system looks great, have you a picture of it filled and operational? I would love to see more.

hi @LuckyDog, having an extra outlet is a benefit if you need it or just cap it off if you dont, the tank i used was 51inch x31 inch by 18 inch roughly 100gallons.as @brokensword said this is an upflow bog where the water is pumped from the pond into 40mm pipe with slits/holes cut in every 2inches and the water rises up through the pea gravel and gravity takes over and it flows back into the pond, i had my feed to the bog directly under the return from my mechanical filter so its relatively clean water going into the bog which goes some way to not clogging the pipes inside the bog i also added a cleaning spout but not everyone does it was more to serve my paranoia of it getting clogged and in the 1st year was as clean as the day it was fitted so i would say if you have it set up right there is no need for a cleaning spout. also i did mine last year and the winter was the worst we have had in uk for many a year and it did not freeze also the plants were at least a month ahead of any in my garden. to start with plantwise i used a lot of watercress which is fast growing but controllable, hope some of this helps, cheers mark

 

[LuckyDog]

Others have followed up and given good advice. One thing I WILL note though is this; when we make our bogs, we like to keep a 6" wall that is higher than the bog water outlet level. This is because over time, as the plant roots fill in, as the pea stone gets a bit clogged, the water level will rise and if you don't have enough area for outpour, it'll rise high enough to flow over the side of the bog. So, keep the outlet of your bog lower than the top to help with this. If you DO see issues over time and fear an overpouring, just start adding more outlet pipes.

Btw, I'm not clear with your statement re the pump; you SHOULD be pushing water from your pond to the bottom of your bog, NOT pulling it using a pump at the bottom of the bog box. If you're using this pump only as a cleanout option down the road, disregard that last.

Thanks again for your time! The pump I was referring to is a hand held/primed tall thingy that will slip inside the gutter down pipe for removing gunk from the void area. I bought it to pump silt from the pond and it works very well (and develops the biceps, too!)
Water IN will go over the top edge of the box, via a pipe, to the bottom. I know the theory but it's the technicalities I get stuck on! You know that old saying, "measure twice, cut once"? Well I could measure 100 times and still be hesitant...
As you say, more pipes can be added in the future if things start to look dodgy. I'm always here to keep an eye on it.

 

[LuckyDog]

hi @LuckyDog, having an extra outlet is a benefit if you need it or just cap it off if you dont, the tank i used was 51inch x31 inch by 18 inch roughly 100gallons.View attachment 143155View attachment 143156View attachment 143157as @brokensword said this is an upflow bog where the water is pumped from the pond into 40mm pipe with slits/holes cut in every 2inches and the water rises up through the pea gravel and gravity takes over and it flows back into the pond, i had my feed to the bog directly under the return from my mechanical filter so its relatively clean water going into the bog which goes some way to not clogging the pipes inside the bog i also added a cleaning spout but not everyone does it was more to serve my paranoia of it getting clogged and in the 1st year was as clean as the day it was fitted so i would say if you have it set up right there is no need for a cleaning spout. also i did mine last year and the winter was the worst we have had in uk for many a year and it did not freeze also the plants were at least a month ahead of any in my garden. to start with plantwise i used a lot of watercress which is fast growing but controllable, hope some of this helps, cheers mark

Thanks for the pics and explanation, it all looks lovely. My box is around half the capacity of yours I think. It's approx 67cms square at the top, and about 62cms square at the bottom and approx 46cms deep. I intend to use clay balls as lighter in weight, and used them before in horticulture. As for plants, I can't wait! Love gardening. I have a lot of bacopa around the place so will probably start with that. I've got iris Siberica and yellow flag in my pond, which I believe are doing the heavy lifting in keeping the water good. However, the yellow flag is an absolute beast and is difficult to keep in check. I want to get rid asap. I may try a piece of Siberica (in a pot) in the bog. Do you eat the watercress? Fantastic in a sandwich with plenty of salt!

 

[addy1]

You are getting great advice! It will be great when done! And your skills are fine