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Well, thought I'd relay my experience with a bog/upflow wetlands cleaning I just did. Took a fair amount of time and made almost every muscle I have ache. I'd like to show what I went through for others and/or get advice for any further 'cleanings'.
What I have is an approximately 4'x4'x4' bog that empties into a small/short stream which then empties into the pond (~2700 gal, ~100 sq. ft surface area). I didn't have this forum for reference when I started, so my bog was built after a 'pro's' version on the web. What I have is a bottom layer of 6" cobble that surrounds my 4" drain pipe, slit with holes. Next, there's about 2' of 2" cobble followed by 2' of pea gravel. The flex pvc coming from my submersible pump goes into the drain pipe which ends in a 12" diameter stack, which is supposed to be used as a clean out. There's the first of my questions;
if this stack is to be used, and by this I mean lowering a pump into the stack and 'backflushing' the bog, how does any debris/detritus work its way down through the entire rock layers and then into the stack if it's sealed? I think this 'stack' is more to be used if the drain pipe gets clogged. If not, I'd like a clue as to how to backflush and get the stone filter area clean instead of having to dig everything up and hand washing.
I figured I had to 'clean' my bog because over the past couple of years, I've been losing water from the bog. This was because I think it was clogged up, either by the plants or by the stones being filled by detritus. This caused the water to not seep upward but find any avenue up to escape the pump's pressure. It began to pour along the sides of the bog and through the stack/clean out. When I put a 'filter' piece inside the stack, it didn't do much besides make the water act more aggressively against the bog's sides.
Soooo, to alleviate the fact I had to slow the flow to the bog (and lessen the filtering power), I decided to clean everything out. When I dug out the stone, there was the expected detritus/debris, especially beneath the foam filter in the stack, as well as a large glob at the drain pipe's end, but overall, I didn't think it was that 'caked'.
Now, I'd like to see if I can do this better in the future and would welcome ideas. I know some might say I should go all pea gravel and if so, please advise it, even if I won't change anything until the next 'cleaning'. I'd still like to know a 'better way' if you have it. Btw, I have no way to add a drain; just the clean out stack. I don't really think 'backflushing' is going to work as I want it to but maybe someone can show me the way. I'd certainly welcome it for the next time. I'm at least of the thought that I'll only dig out the top 2' of pea gravel next time and wash/clean that. Unless someone can tell me why that wouldn't be a good idea and I need to completely take it down to the bottom again.
And for anyone wondering, there was no obnoxious smell at all; just clean pond water, so no anaerobic issues at all, despite it being shut down for the winter.
I think some of my 'errors' were; putting the sub pump too low in the pond initially. I have had it about mid-height for the past two years. I don't have any 'pre-filter', all I have now is a window screen 'bag' around it to keep out anything large. Is this enough?
Another thing I did wrong was to put 'large' plants in my bog; last year, I had a 7' black taro, and also too many yellow flag irises. I'm planning on putting in lower growing plants like pennywort or some dwarf papyrus.
A last question would be; last year to help alleviate the water loss, I lessened the flow to the bog so it merely trickled. Is there a better flow rate? That is, if faster, does it clean better? Does it act as a better biofilter if I blast the water through or trickle it?
Anyway, I never thought I'd have to 'clean' this bog but found out otherwise. If my methodology is wrong, I'd like to know. I think my changes will help and the bog lasted 3 good years before I began having issues in year 4 then 5.
Thanks for listening and any help/discussion.
Michael
What I have is an approximately 4'x4'x4' bog that empties into a small/short stream which then empties into the pond (~2700 gal, ~100 sq. ft surface area). I didn't have this forum for reference when I started, so my bog was built after a 'pro's' version on the web. What I have is a bottom layer of 6" cobble that surrounds my 4" drain pipe, slit with holes. Next, there's about 2' of 2" cobble followed by 2' of pea gravel. The flex pvc coming from my submersible pump goes into the drain pipe which ends in a 12" diameter stack, which is supposed to be used as a clean out. There's the first of my questions;
if this stack is to be used, and by this I mean lowering a pump into the stack and 'backflushing' the bog, how does any debris/detritus work its way down through the entire rock layers and then into the stack if it's sealed? I think this 'stack' is more to be used if the drain pipe gets clogged. If not, I'd like a clue as to how to backflush and get the stone filter area clean instead of having to dig everything up and hand washing.
I figured I had to 'clean' my bog because over the past couple of years, I've been losing water from the bog. This was because I think it was clogged up, either by the plants or by the stones being filled by detritus. This caused the water to not seep upward but find any avenue up to escape the pump's pressure. It began to pour along the sides of the bog and through the stack/clean out. When I put a 'filter' piece inside the stack, it didn't do much besides make the water act more aggressively against the bog's sides.
Soooo, to alleviate the fact I had to slow the flow to the bog (and lessen the filtering power), I decided to clean everything out. When I dug out the stone, there was the expected detritus/debris, especially beneath the foam filter in the stack, as well as a large glob at the drain pipe's end, but overall, I didn't think it was that 'caked'.
Now, I'd like to see if I can do this better in the future and would welcome ideas. I know some might say I should go all pea gravel and if so, please advise it, even if I won't change anything until the next 'cleaning'. I'd still like to know a 'better way' if you have it. Btw, I have no way to add a drain; just the clean out stack. I don't really think 'backflushing' is going to work as I want it to but maybe someone can show me the way. I'd certainly welcome it for the next time. I'm at least of the thought that I'll only dig out the top 2' of pea gravel next time and wash/clean that. Unless someone can tell me why that wouldn't be a good idea and I need to completely take it down to the bottom again.
And for anyone wondering, there was no obnoxious smell at all; just clean pond water, so no anaerobic issues at all, despite it being shut down for the winter.
I think some of my 'errors' were; putting the sub pump too low in the pond initially. I have had it about mid-height for the past two years. I don't have any 'pre-filter', all I have now is a window screen 'bag' around it to keep out anything large. Is this enough?
Another thing I did wrong was to put 'large' plants in my bog; last year, I had a 7' black taro, and also too many yellow flag irises. I'm planning on putting in lower growing plants like pennywort or some dwarf papyrus.
A last question would be; last year to help alleviate the water loss, I lessened the flow to the bog so it merely trickled. Is there a better flow rate? That is, if faster, does it clean better? Does it act as a better biofilter if I blast the water through or trickle it?
Anyway, I never thought I'd have to 'clean' this bog but found out otherwise. If my methodology is wrong, I'd like to know. I think my changes will help and the bog lasted 3 good years before I began having issues in year 4 then 5.
Thanks for listening and any help/discussion.
Michael