What is the correct way to build a bog filter and are there substitutes for bog filter media?

[morewater]

"Awesome, so the liner is key if i want clarity. I will look for inexpensive liner solutions that other have suggested in other threads."
________________________________________________________________________________

In any project, if you're going to go the time and the expense to create something, don't skimp on the basic elements for successful completion.

Going for the "inexpensive liner" may very well save you a couple of hundred bucks, but replacing it will cost you many hours of labor, plus the cost of either using another cheap liner (in which case you're right back to where you started), or buying what you should have bought in the first place, proper liner.

45mil EPDM.

 

[ASchell90]

Agreed. Some have suggested asking roofing companies or local farms/hydroponics operations for assistance as a way to reduce costs. Our liner for our tilapia pond was leftover from a locally manmade reservoir. I never want to pay full price for anything i can get for less is all. Dont worry, 45 mil epdm is what ill use once i find that deal im looking for.

I guess the appeal for me was the natural element of the earthenbottom pond. (And the perceived ease of construction.) But with everybodys input it seems that a liner would make the most sense in this situation.

 

[Koi4JT]

All of the previous comments are good. Now, let me summarize some of my points of view.
1) The bog should really have "pea" gravel for proper filtration and be lined with good pond liner material. Swimming pools use sand!
2) The bog needs to be deep, not long and should equal about 10% of the pond's volume. Water is usually pumped into the bottom of the bog through say 3/4" PVC piping constructed in a "H" pattern, center fed from the pump with each leg having numerous 1/4" holes (drilled through both sides) spaced every 3 to 6 inches. The "H" distribution piping is covered by 4" corrugated PVC drain pipe cut horizontally in half, so each leg is covered. Next cover the corrugated piping with about 12 to 18" of the pea gravel. Cover this layer of pea gravel with 1" thick heavy filtration media. Then fill the rest of the bog up with the pea gravel. The bog should have a discharge chute that is below the top of the liner and discharges into your pond.
3) The reason for the filter media is to reduce the possibility of any bog plants roots from working their way down and clogging up the distribution piping.
4) For reference, my bog is 24" x 72" x 48" deep and filters both a 1,500 gal and a 1,000 gal pond with lots of fish.
5) Depending on how much filtration you need to do, which would be fairly minimal if your pond is lined (which I highly recommend) but could be substantial if not, you will need to periodically backwash the bog. To do this, I connect a separate pump to the supply pipe to the bog and suck the water out from the bottom, which adding water to the top with a garden hose. I do this until the water discharge become clear. In my situation, my pond has a lot of fish in it, so I usually backwash the bog ever 2-3 years.
6) Bogs are great for fish ponds as they develop good bacteria that digest the fish's waste and keep the pond water crystal clear all year long. But in your case, with no fish and just a swimming hole, you will need chlorination assuming you don't want to get sick from eventually polluted water, hence reason #1 to fully line your pond. Reason #2 is that an unlined chlorinated pond will quite possible leach into the water table which I dare say that the EPA won't appreciate.
7) In constructing your pond. your really need to support the top 2-3 feet of the perimeter, preferable with concrete architectural block (shaped like a 6 sided diamond) and readily available at Lowe's or HD. Failure to adequately support the upper perimeter will most likely result in gradual cave-ins. Also, tuck in the pond liner half way up this perimeter wall from the inside to the outside leaving the top several rows of block exposed. Grade the surround landscape to just about 1/2 below the top course of blocks. Use a skimmer on a side opposite of the bog's discharge chute to allow natural circulation through the pond.
8) Finally,depending on the elevation of the bog in relation to the pond, I highly recommend installing a check valve on the pipe feeding the bog to prevent dirty water from draining back into the pond if and when the pump is off line.

Hope this helps and good luck!

 

[ASchell90]

Hey there Koi4JT! I appreciate your comments, the check valve was something I had not thought of and makes total sense, it is those little things that when forgotten can create a terrible mess. Thank you. I have a couple updates and a couple more questions which have arisen.

Following some other people's suggestions I began posting and communicating with people on mud pond forums and fishing lake forums. There are very few people who have tried and have been successful with keeping a earthenbottom pond clear. In fact, as Meyer Jordan pointed out to begin with, it is impossible without being prohibitively expensive. The one recommendation I received was to build my bog on top of a network of milk crates or something similar and install a bottom drain to flush it out, a process similar to what you have suggested. Apparently this was done on a much larger scale and worked to some degree. My thought process was maybe build a raised a portion, like a box or cage, on the deepest end of the bog with an opening on top where I could drop in a pump to remove the sludge as I flush it out from the other side. It wouldn't be too difficult to build, I have lots of scrap metal, but I am not sure if that even makes sense or is necessary. Other people have dug separate ponds, as big as my whole system, just to use as a massive bio/media filter. In my mind, the "bog" I am constructing would work in a similar, likely less effective, way.

Reading about the safety of swimming holes and microbial growth is a disenchanting exercise and I recommend it to absolutely nobody. I am fully aware of the risks of bodies of water and will do my best to provide a safe environment for myself and others but there is danger everywhere. I can only accomplish so much with the resources I have available and fail to see the logic in spending an inordinate amount of time and money on keeping a "natural" body of water sterile. As far as chlorinating the pond I do not think that is an option for me. Our family group that lives on the property absolutely prohibits the use of bleach, caustic chemicals, pesticides, etc. They are very, very, environmentally conscience. (For example, I live in a separate house and they get upset if I use bleach to wash my sidewalks because it "kills the plants and gets in the aquifer". You have to love old hippies but you cannot always reason with them.) I spoke with a fellow who may be able to help me procure a UV clarifier in the long term but I have no plan until then. In addition, to actually sterilize a pond this size with UV would cost 1000's. I have to do more research to see if a smaller UV sterilizer on a pond this size would do any good at all or just waste electricity. If that plan does not work than I will have to hope that aeration and the introduction of good bacteria will be enough to keep the body of water relatively safe.

I have been searching for cheaper alternatives to lining the pond and constructing a filtering system and have accumulated quite the hodge podge of things to use. I have some liner scraps from previous projects and some my neighbor was planning on using but doesn't have a use for now, 300 lbs of bentonite clay, a large stack of cinder blocks I forgot I had on a pallet in the woods, and a pile of leftover cypress boards from a deck we built. The plan is to drain the pond, pack down the clay, seal the edges where it may leak with the bentonite clay. Because the hole holds water would it be completely insane to use the liner I have to line the pond in overlapping portions solely to minimize the amount of debris that is kicked up? I believe I already have a good solid basin, I do not think I need the liner to hold the water in. The idea is to drape the liners over the sides, tuck them in or under the berm, and then lay a liner on the bottom. I could use the random cinder blocks to construct a ring around the base which would prevent the liner from floating up at all. I am open to criticism and fresh ideas. I cannot afford a full liner at the moment and waiting on funds would delay the project for an extended period.

I filled the pond to maximum capacity overnight (accidentally on purpose) and monitored the water as it drained out to find leaks and measure overall drop over the course of a hot week. For reference the pond has 2 foot tall "berms" circling the entire hole. I don't know if you can tell by looking at those pictures but the ground level is where the layer of dirt is when you look at the striation, the mounds above that is just the clay that I haven't been able to move around. The water filled and was overflowing the lowest edge of the mounds, it was pretty scary actually, I thought all those layers where you can see it already eroding away would erode further and cause the "berms" to cave in with it.

The water drained out under the berms, where the excavated clay just sits on the topsoil, but stayed steady after that for a week. So, the soil ring at the top is either super saturated or only allowing small seepage which works for me. The water settled out and was a nice clear green color until I entered the pond and would become that murky grey once again.

I dont have many days to work with and didnt want a giant stagnant water hole while I wait for my time off so I drained the pond yesterday. To nobody's surprise there has been significant erosion on the two walls visible in the picture above and a nice thick (foot deep if not more) layer of mud that is now sitting at the bottom of my project hole. To prevent more erosion I though about sinking cypress logs vertically at each corner of the hole and then laying cypress boards behind them to form a barrier. I could also just allow the erosion to continue until it forms a more natural slope and then lay the liner over that after I pack it down.

Please keep in mind I cannot keep this hole dry, there is a continual ground seep from two spots that feed this pond. In order to get the pond free of muck so I can line it I need to continually pump out the water and shovel out the mud. OR I am going to rent a diaphragm pump and let the machine do the heavy lifting when I have weekend off.

Lots of fun in the mud for me to come. Again, all criticism, skepticism, and input is appreciated! Thank you all for your help.

 

[Koi4JT]

Hey there Koi4JT! I appreciate your comments, the check valve was something I had not thought of and makes total sense, it is those little things that when forgotten can create a terrible mess. Thank you. I have a couple updates and a couple more questions which have arisen.

Following some other people's suggestions I began posting and communicating with people on mud pond forums and fishing lake forums. There are very few people who have tried and have been successful with keeping a earthenbottom pond clear. In fact, as Meyer Jordan pointed out to begin with, it is impossible without being prohibitively expensive. The one recommendation I received was to build my bog on top of a network of milk crates or something similar and install a bottom drain to flush it out, a process similar to what you have suggested. Apparently this was done on a much larger scale and worked to some degree. My thought process was maybe build a raised a portion, like a box or cage, on the deepest end of the bog with an opening on top where I could drop in a pump to remove the sludge as I flush it out from the other side. It wouldn't be too difficult to build, I have lots of scrap metal, but I am not sure if that even makes sense or is necessary. Other people have dug separate ponds, as big as my whole system, just to use as a massive bio/media filter. In my mind, the "bog" I am constructing would work in a similar, likely less effective, way.

Reading about the safety of swimming holes and microbial growth is a disenchanting exercise and I recommend it to absolutely nobody. I am fully aware of the risks of bodies of water and will do my best to provide a safe environment for myself and others but there is danger everywhere. I can only accomplish so much with the resources I have available and fail to see the logic in spending an inordinate amount of time and money on keeping a "natural" body of water sterile. As far as chlorinating the pond I do not think that is an option for me. Our family group that lives on the property absolutely prohibits the use of bleach, caustic chemicals, pesticides, etc. They are very, very, environmentally conscience. (For example, I live in a separate house and they get upset if I use bleach to wash my sidewalks because it "kills the plants and gets in the aquifer". You have to love old hippies but you cannot always reason with them.) I spoke with a fellow who may be able to help me procure a UV clarifier in the long term but I have no plan until then. In addition, to actually sterilize a pond this size with UV would cost 1000's. I have to do more research to see if a smaller UV sterilizer on a pond this size would do any good at all or just waste electricity. If that plan does not work than I will have to hope that aeration and the introduction of good bacteria will be enough to keep the body of water relatively safe.

I have been searching for cheaper alternatives to lining the pond and constructing a filtering system and have accumulated quite the hodge podge of things to use. I have some liner scraps from previous projects and some my neighbor was planning on using but doesn't have a use for now, 300 lbs of bentonite clay, a large stack of cinder blocks I forgot I had on a pallet in the woods, and a pile of leftover cypress boards from a deck we built. The plan is to drain the pond, pack down the clay, seal the edges where it may leak with the bentonite clay. Because the hole holds water would it be completely insane to use the liner I have to line the pond in overlapping portions solely to minimize the amount of debris that is kicked up? I believe I already have a good solid basin, I do not think I need the liner to hold the water in. The idea is to drape the liners over the sides, tuck them in or under the berm, and then lay a liner on the bottom. I could use the random cinder blocks to construct a ring around the base which would prevent the liner from floating up at all. I am open to criticism and fresh ideas. I cannot afford a full liner at the moment and waiting on funds would delay the project for an extended period.

I filled the pond to maximum capacity overnight (accidentally on purpose) and monitored the water as it drained out to find leaks and measure overall drop over the course of a hot week. For reference the pond has 2 foot tall "berms" circling the entire hole. I don't know if you can tell by looking at those pictures but the ground level is where the layer of dirt is when you look at the striation, the mounds above that is just the clay that I haven't been able to move around. The water filled and was overflowing the lowest edge of the mounds, it was pretty scary actually, I thought all those layers where you can see it already eroding away would erode further and cause the "berms" to cave in with it.

The water drained out under the berms, where the excavated clay just sits on the topsoil, but stayed steady after that for a week. So, the soil ring at the top is either super saturated or only allowing small seepage which works for me. The water settled out and was a nice clear green color until I entered the pond and would become that murky grey once again.

I dont have many days to work with and didnt want a giant stagnant water hole while I wait for my time off so I drained the pond yesterday. To nobody's surprise there has been significant erosion on the two walls visible in the picture above and a nice thick (foot deep if not more) layer of mud that is now sitting at the bottom of my project hole. To prevent more erosion I though about sinking cypress logs vertically at each corner of the hole and then laying cypress boards behind them to form a barrier. I could also just allow the erosion to continue until it forms a more natural slope and then lay the liner over that after I pack it down.

Please keep in mind I cannot keep this hole dry, there is a continual ground seep from two spots that feed this pond. In order to get the pond free of muck so I can line it I need to continually pump out the water and shovel out the mud. OR I am going to rent a diaphragm pump and let the machine do the heavy lifting when I have weekend off.

Lots of fun in the mud for me to come. Again, all criticism, skepticism, and input is appreciated! Thank you all for your help.

Hi Aschell90, OK I understand a bit more of were you are and where you want to go, so here are some more ideas and comments:

1) See if you can get hold of some decent roofing EPDM. It should be cheaper than pond liner which in your case doesn't matter because roofing EPDM can leach out plasticizers which are toxic to fish but won't affect you.
2) The bog as I referenced will become a "good" bacterial source that will or should keep the water reasonably clean being similar to lake water, but don't drink it.
3) Aeration will also help maintain decent water quality and if you utilize the flow through concept I previously mentioned (bog discharge to skimmer intake) your should eliminate any stagnation, which is the real problem causer.
4) I still recommend the CMU (concrete block) top perimeter border to stabilize the earth up to and beyond the pond. You should lay the liner as I previously mentioned but not necessarily do you need to totally line the pond. You could leave whatever FLAT bottom exposed. The liner is necessary to protect the excavated sides from erosion, which will totally mess up your hard work, but not necessarily so to retain the water. Nevertheless, a totally lined pond is the best. If you plan to use the bentonite clay, just fill the concrete blocks. If you use this stuff behind the blocks to fill the gap between the blocks an the earth, the bentonite will expand when wet and could possibly push you blocks into the ponds. I would recommend just reuse some of the better quality excavated dirt to fill in the blanks.
5) Very Important! You must establish a fence at least 48" tall all the way around your pond with a positive latching gate to eliminate the Attractive Nuisance you have created. It should protect you (legally) from wandering children, pets and wayward hippies, but not snakes or frogs.
6) And remember, you are trying to develop a miniature pond to cool your heels in, not a swimming pool per se. But keep in mind to build in a way to easily get out of the water via a ladder or something to make it easy to exit the pond.

Like someone somewhere said, nothing is ever easy!

 

[Meyer Jordan]

If you follow the 3:1 slope recommended for a recreational pond (some sources recommend 4:1 even 5:1) there should be little problem with erosion.

 

[angelmandi]

I have been using a natural bog filter on our large outdoor koi pond since 2005, and constructed a mechanical bog type filter in a stock tank for our basement, as we move our koi indoors during the winter months. We are in zone 5 NW PA. In our natural bog outside, we made a perforated PVC pipe for water to filter up through the media, and re-entering pond through wier. Works great. The only thing I would suggest, is perhaps double-lining your bog, especially if using a big larger rocks at the bottom. We have smaller river rock sized, inch or less diameter at the bottom, so as not to plug up PVC holes, with pea gravel on top of that. As you fill up your pond after your bog and pond are constructed, and then plug in your pump, the bog will fill up so water is on top until it goes back into the pond. We have our gravel up, so there is about 2 inches of water room before it flows into wier. I would also suggest some plants that have deep roots to plant in your rocks. We have cattails as the majority of our bog at this point. They have kind of taken over. But they do a super job with deep roots, cleaning water. Our first year, we used a lot of floating water lettuce and water hyacinths in bog, while rooting pkants were getting established. We don't need those know, but they were essential in clesaning water that first year. Bogs are awesome. We have always had crystal clear water since the first initial week of muddiness in a new pond.

 

[pastures]

Greetings ASchell90.

I followed with much interest your discussion about constructing a bog filter in the Garden Pond Form November issue. I have some questions about your logic/thought processes.

(1) Your chosen bog depth of 14": is this a compromised depth of possibly two depths for water flora - one being at 2' and a second at less than 1'?

(2) Do you choose to line the bog simply to prevent leakage into the ground below it? I understand that gravel, regardless of size, will add surface area for nutrient-consuming microorganisms to adhere, besides anchoring water flora; otherwise, most soils, such as in your swimming area, already host numerous natural nutrient-consuming microorganisms. [SLIME on rocks is good.]

(3) One of your photos depict a living tree nearby which would spell LEAKAGE immediately to a damned pond via its roots. In your particular situation, however, you specified that your hillside pond location has a plentiful water table moving through your pond area. Therefore, you should experience no leakage problems? During a dry season, would not the weight of your pond water simply push itself downhill as the soil downhill begins to dry up? Your blue/white bottom clay certainly will not leak water, but would not your sides will leak horizontally?

(4) I assume that bogs, about which I too am trying to educate myself, naturally consume generated nutrients from fish, wildlife, flora and from themselves decaying. However, the water carrying these nutrients move very slowly if at all. Do you plan to install a flow rheostat on your circulating system? Your discharge system, combined with Koi4JT' suggestions, sounds reasonable. Since I am trying to construct zero maintenance and zero outside energy bogs for ponds here in southeast Louisiana, back-washing a bog is out of my realm and question. I may be dreaming, but I definitely do not want to entertain a heavy maintenance schedule for myself or for my clients.

(5) Lastly, what water flora will you attempt to utilize in you bog and in your swimming area, if applicable? The problem I have encountered in my research of nutrient-consuming water flora is simply they spread quickly in nutrient-rich locations. The only corrective solution I have conceived so far, is to either limit their spread physically with barriers (dry surface land and/or sides of the pond-bog) and/or sudden depth changes. Here in Louisiana, sticky clay dominates our ground and can support 1:3 slopes, and our water table normally lies within 1" of the surface.

I plan to continue watching your progress and wish you much luck and enjoyment. Pastures.

 

[addy1]

I have been using a natural bog filter on our large outdoor koi pond since 2005, and constructed a mechanical bog type filter in a stock tank for our basement, as we move our koi indoors during the winter months. We are in zone 5 NW PA. In our natural bog outside, we made a perforated PVC pipe for water to filter up through the media, and re-entering pond through wier. Works great. The only thing I would suggest, is perhaps double-lining your bog, especially if using a big larger rocks at the bottom. We have smaller river rock sized, inch or less diameter at the bottom, so as not to plug up PVC holes, with pea gravel on top of that. As you fill up your pond after your bog and pond are constructed, and then plug in your pump, the bog will fill up so water is on top until it goes back into the pond. We have our gravel up, so there is about 2 inches of water room before it flows into wier. I would also suggest some plants that have deep roots to plant in your rocks. We have cattails as the majority of our bog at this point. They have kind of taken over. But they do a super job with deep roots, cleaning water. Our first year, we used a lot of floating water lettuce and water hyacinths in bog, while rooting pkants were getting established. We don't need those know, but they were essential in clesaning water that first year. Bogs are awesome. We have always had crystal clear water since the first initial week of muddiness in a new pond.

I built my pond in 2010, it is around 9k gallons, second in size is 1000k , with a 85 foot stream and 8 other small ponds in the circulation. The only filter I have is my bog, which is huge. The bog is around 26 ft x 4.5 ft x 2 ft. The majority of the bog plants roots only go down 4 - 6 inches. The grasses go a lot deeper.
Since the initial turn on, i.e. the unwashed 38000 lbs of pea gravel worth of dirt got circulated, the pond water stays in perfect condition, no green water even in the spring, no string algae in the main ponds. I get some in the smaller slow flowing warm water ponds, fishless, I leave it for the critters.

My piping is cut with slashes, facing down, with a extra piece of liner below the pipes, just scraps of liner, for the constant flow of water hitting the liner.

There are parts of the bog that are above water parts below water. The plants grow like weeds, they suck enough out of the pond water that I hardly ever need to clean the bottom of the pond. No debris accumulates. I attempt to net it every few years, but usually only get 1/2 of a 5 gallon bucket of debris, so usually don't bother. No bottom drain. I have never cleaned the bog, no need to. It never smells even after being off for the winter season.

Can you tell I LOVE MY BOG! lol the pond is essentially no care except grooming excessive plant growth.


This is a today shot, shut down for the winter. I have an external pump and the surface area of the bog is large it really cools the water.

 

[ASchell90]

Greetings ASchell90.

I followed with much interest your discussion about constructing a bog filter in the Garden Pond Form November issue. I have some questions about your logic/thought processes.

(1) Your chosen bog depth of 14": is this a compromised depth of possibly two depths for water flora - one being at 2' and a second at less than 1'?

(2) Do you choose to line the bog simply to prevent leakage into the ground below it? I understand that gravel, regardless of size, will add surface area for nutrient-consuming microorganisms to adhere, besides anchoring water flora; otherwise, most soils, such as in your swimming area, already host numerous natural nutrient-consuming microorganisms. [SLIME on rocks is good.]

(3) One of your photos depict a living tree nearby which would spell LEAKAGE immediately to a damned pond via its roots. In your particular situation, however, you specified that your hillside pond location has a plentiful water table moving through your pond area. Therefore, you should experience no leakage problems? During a dry season, would not the weight of your pond water simply push itself downhill as the soil downhill begins to dry up? Your blue/white bottom clay certainly will not leak water, but would not your sides will leak horizontally?

(4) I assume that bogs, about which I too am trying to educate myself, naturally consume generated nutrients from fish, wildlife, flora and from themselves decaying. However, the water carrying these nutrients move very slowly if at all. Do you plan to install a flow rheostat on your circulating system? Your discharge system, combined with Koi4JT' suggestions, sounds reasonable. Since I am trying to construct zero maintenance and zero outside energy bogs for ponds here in southeast Louisiana, back-washing a bog is out of my realm and question. I may be dreaming, but I definitely do not want to entertain a heavy maintenance schedule for myself or for my clients.

(5) Lastly, what water flora will you attempt to utilize in you bog and in your swimming area, if applicable? The problem I have encountered in my research of nutrient-consuming water flora is simply they spread quickly in nutrient-rich locations. The only corrective solution I have conceived so far, is to either limit their spread physically with barriers (dry surface land and/or sides of the pond-bog) and/or sudden depth changes. Here in Louisiana, sticky clay dominates our ground and can support 1:3 slopes, and our water table normally lies within 1" of the surface.

I plan to continue watching your progress and wish you much luck and enjoyment. Pastures.

1/2. The depth of the bog was an accident. I built the bog portion by sectioning off a third of the undug area around my pond, digging out the top soil, and then building a small retaining wall. I was shooting for a one foot deep bog and over did it a little bit. I lined the bog because I was seeing a lot of leakage through the berm and top soil (and I had a piece of scrap epdm liner that I fit perfectly).

3. Oh that beautiful live oak. The story behind this whole adventure is a long and interesting one which deserves a quick retelling. We live on an old orange grove atop a hill; I actually live in what was once a small barn/garage tucked back in the woods. The previous owner noticed some strange water behavior during his time here and discovered that we have a small wet weather spring about thirty feet behind my barn/house. His crazy idea was to build a small pond, stock it with beautiful fish, and sit up under that tree and whistle away the days looking at them. I liked the idea so much I found a shovel before I found my common sense and it has been all mud and sweat sense then.
I am sure there would be leakage due to the water leaking downhill, my initial plan was to line the pond with bentonite clay but I did not make a correct slope because I wanted more of a "pool" rather than a pond. Once I realized my mistake the excavator was already back at the rental supply place. The plan now is to line the walls and reinforce them in some way to prevent the eventual erosion.

4. I have no idea what a flow rheostat is. My ideas for making the bog easier to clean are due to the way my pond is constructed which I am sure will result in a substantial amount of silt to accumulate in the bog due to it not being lined properly. If I do line it completely, as others have done, it is my understanding that a properly constructed bog is generally no maintenance for years.

5. LOTS OF CATTAILS! I have not actually done enough research as far as the best local flora to use in my bog but plan on doing so and would love suggestions. I have a local man with a pond who has some interesting lilies and rushes that he will happily give me which I plan on using around the edges and maybe even in the swimming portion itself.

Thank you so much, and best of luck to you!

 

[ASchell90]

Hi Aschell90, OK I understand a bit more of were you are and where you want to go, so here are some more ideas and comments:

1) See if you can get hold of some decent roofing EPDM. It should be cheaper than pond liner which in your case doesn't matter because roofing EPDM can leach out plasticizers which are toxic to fish but won't affect you.
2) The bog as I referenced will become a "good" bacterial source that will or should keep the water reasonably clean being similar to lake water, but don't drink it.
3) Aeration will also help maintain decent water quality and if you utilize the flow through concept I previously mentioned (bog discharge to skimmer intake) your should eliminate any stagnation, which is the real problem causer.
4) I still recommend the CMU (concrete block) top perimeter border to stabilize the earth up to and beyond the pond. You should lay the liner as I previously mentioned but not necessarily do you need to totally line the pond. You could leave whatever FLAT bottom exposed. The liner is necessary to protect the excavated sides from erosion, which will totally mess up your hard work, but not necessarily so to retain the water. Nevertheless, a totally lined pond is the best. If you plan to use the bentonite clay, just fill the concrete blocks. If you use this stuff behind the blocks to fill the gap between the blocks an the earth, the bentonite will expand when wet and could possibly push you blocks into the ponds. I would recommend just reuse some of the better quality excavated dirt to fill in the blanks.
5) Very Important! You must establish a fence at least 48" tall all the way around your pond with a positive latching gate to eliminate the Attractive Nuisance you have created. It should protect you (legally) from wandering children, pets and wayward hippies, but not snakes or frogs.
6) And remember, you are trying to develop a miniature pond to cool your heels in, not a swimming pool per se. But keep in mind to build in a way to easily get out of the water via a ladder or something to make it easy to exit the pond.

Like someone somewhere said, nothing is ever easy!

I have some scraps of EPDM and some other less durable scraps. I have all my sources keeping their eyes peeled for more and am hoping for that big perfect find one of these days. I do not think an in the wall skimmer would be possible with my current situation but that is my ultimate goal. I have been researching some of those in pond skimmers and was hoping that in conjunction with the aeration from the weir and the aerator would create enough to prevent stagnation.

My fear with the concrete block layer is that with the slope being so steep that they would cause the tops to cave in. I have thought about caving the walls in myself, creating a more shallow pool, creating a more natural slope, and just lining the entire thing as suggested. I really enjoy the depth that it is now but if that is not the best option than I need to rethink it.

I plan on mixing the clay in with the ring/layer of sandy soil around the edge to create a more impermeable seal. Or using it to seal the major leak points that I have found. If I were to use the concrete blocks I could just use the massive piles of excavated clay/dirt to pack the voids and fill any gaps behind it.

This project is not attractive but it sure is a nuisance. I have the fence posts and everything ready to go up as soon as I am sure I will not be using anymore heavy equipment. And don't tell the SO about the snakes and spiders yet, I just convinced her that I would have this done before next summer.

Who know just trying to dig a good old fashin' swimmin' hole would be such hard work??

 

[Meyer Jordan]

I have some scraps of EPDM and some other less durable scraps. I have all my sources keeping their eyes peeled for more and am hoping for that big perfect find one of these days. I do not think an in the wall skimmer would be possible with my current situation but that is my ultimate goal. I have been researching some of those in pond skimmers and was hoping that in conjunction with the aeration from the weir and the aerator would create enough to prevent stagnation.

My fear with the concrete block layer is that with the slope being so steep that they would cause the tops to cave in. I have thought about caving the walls in myself, creating a more shallow pool, creating a more natural slope, and just lining the entire thing as suggested. I really enjoy the depth that it is now but if that is not the best option than I need to rethink it.

I plan on mixing the clay in with the ring/layer of sandy soil around the edge to create a more impermeable seal. Or using it to seal the major leak points that I have found. If I were to use the concrete blocks I could just use the massive piles of excavated clay/dirt to pack the voids and fill any gaps behind it.

This project is not attractive but it sure is a nuisance. I have the fence posts and everything ready to go up as soon as I am sure I will not be using anymore heavy equipment. And don't tell the SO about the snakes and spiders yet, I just convinced her that I would have this done before next summer.

Who know just trying to dig a good old fashin' swimmin' hole would be such hard work??

If you have not already seen this publication then I would recommend that you download it and use it for reference. It is very complete, though somewhat technical in spots, and discusses recreational ponds.
https://nrcspad.sc.egov.usda.gov/distributioncenter/product.aspx?ProductID=115

 

[ASchell90]

Thank you so much. Ill read the entire thing, i appreciate it.

 

[Meyer Jordan]

Also, since you are looking for a type of filtration that would aid in water clarity and quality, instead of leaning towards a full-blown constructed wetlands filter ("bog") and you will have no fish, a basic phyto-filter similar to the graphic posted below, would provide the aesthetic quality of a planted area. the biofiltration of the plants rhizosphere plus provide the mechancal filtration that you need in the form of a settling chamber. This configuration can be used with earthen-bottom ponds as there is no possibility of clogging and access for maintenance is simple. I have used a similar set-up on earthen ponds that I have 'restored' in the past.

 

[ASchell90]

Also, since you are looking for a type of filtration that would aid in water clarity and quality, instead of leaning towards a full-blown constructed wetlands filter ("bog") and you will have no fish, a basic phyto-filter similar to the graphic posted below, would provide the aesthetic quality of a planted area. the biofiltration of the plants rhizosphere plus provide the mechancal filtration that you need in the form of a settling chamber. This configuration can be used with earthen-bottom ponds as there is no possibility of clogging and access for maintenance is simple. I have used a similar set-up on earthen ponds that I have 'restored' in the past.
View attachment 95991

Oh man that looks absolutely perfect. It is like you read my mind. Thank you so much. I am glad to know that a system like that has been used with success before. This could definitely be the solution i am looking for.