To bog or not to bog.

[brandonsdad02]

So I'm going with a bog and later ill b installing a skippy also if needed. But my new question is i have a 2" pipe running at the bottom of my bog and i have 3/8" holes drilled every 6" and the pipe is 7' long. Will them 3/8" holes b ok and not restrict my flow.

That most likely will restrict your flow depending on the size of the pump you use. When I was installing my bog, I cut the slits in the pipe and turned my pump on. I kept adding slits until there was just a small trickle of water coming out of my clean out pipe.

 

[gello22]

Stouty109

If my word problem skills are correct you have 14 holes which would be about half the area of the 2" pipe. If the holes go all the way through ie 2 holes every 6" then the areas will be roughly equal, but many small holes are still more restrictive than one large one.

How much flow are you expecting?

 

[Waterbug]

So I'm going with a bog and later ill b installing a skippy also if needed. But my new question is i have a 2" pipe running at the bottom of my bog and i have 3/8" holes drilled every 6" and the pipe is 7' long. Will them 3/8" holes b ok and not restrict my flow.

Depends on what you're sending into the pipe.

The pipe deals at the bottom of bogs is a fairly new thing (last 5-10 years). Bogs worked fine without them. The pipe actually allows water to travel some distance down the pipe, bypassing much of the bog. Water takes the path of least resistance. I think people just like the idea of adding pipes, more fun. But for function dumping the water in one end and letting it find it's path thru the bog is more efficient for settling waste and bio conversion. A molecule of ammonia has a greater chance of bumping into a bacteria converter the further thru the media it has to travel.

I don't think adding pipe really hurts anything very much because bogs aren't great bio converters anyways so no big deal one way or the other. But I wouldn't spend a lot of time worrying about pipe hole sizes, number of holes, etc. Doesn't matter. If all the holes clog and the water backup up and came out where the pipe entered the bog the removal of waste would probably be improved. But it's not like anyone ever actually measures bogs.

 

[addy1]

Depends on what you're sending into the pipe.

The pipe deals at the bottom of bogs is a fairly new thing (last 5-10 years). Bogs worked fine without them. The pipe actually allows water to travel some distance down the pipe, bypassing much of the bog. Water takes the path of least resistance. I think people just like the idea of adding pipes, more fun. But for function dumping the water in one end and letting it find it's path thru the bog is more efficient for settling waste and bio conversion. A molecule of ammonia has a greater chance of bumping into a bacteria converter the further thru the media it has to travel.

I don't think adding pipe really hurts anything very much because bogs aren't great bio converters anyways so no big deal one way or the other. But I wouldn't spend a lot of time worrying about pipe hole sizes, number of holes, etc. Doesn't matter. If all the holes clog and the water backup up and came out where the pipe entered the bog the removal of waste would probably be improved. But it's not like anyone ever actually measures bogs.

Tend to disagree with you on the water missing most of the bog. I see water flow coming through my 25 foot bog the entire length of it. Two pipes feeding pond water into the bog.

No science behind what I observe, I don't fight string algae, don't fight green water, just filter with my bog. Never had bad water tests, water clear, bottom of pond staying pretty muckless. There is some but no great amount. Fish look healthy, plants healthy. So something is working right.

 

[Waterbug]

Some water travels down the entire pipe and exits close to the out flow. So total distance thru gravel would be from the pipe to the out flow. Depends on the set up but that can a very short distance, maybe 12-36". If all water is dumped into one end it must travel the entire length of the bog at a minimum. Hopefully that's a lot longer distance, but does depend on the set up.

Water will take the path of least resistance so all other things being equal more water will flow thru a hole closer to the outflow than the same size hole further away.

There's a will known concept in gravel and sand filters, from ponds to wastewater treatment to swimming pools, called "channeling". The problem is water will find the path of least resistance and only follow that which reduces the filter's usefulness . The pipe creates a channel.

I'd also add that being able to "see" water flowing the entire length a bog would not be a good thing because surface water wouldn't really be going thru the bog at all. To see below the gravel would take x ray vision. But I'd assume there was some water movement coming out of all pipe holes. The issue is the amount. With no pipe 100% of the water has to move the entire length of the bog. With a distribution pipe that number can only decrease.

I think people kind of miss the entire purpose of using pea gravel in a bog. It's to create a matrix of small openings that water must move thru...exactly the same thing people are trying to do with distribution pipe...but the gravel is much, much better at this. It creates thousands of tiny little holes to distribute the water.

 

[addy1]

For my set up, if I plumbed it for the water to flow over the pea gravel back into the pond via a water fall, the path of least resistance would be over the top of the pea gravel right back into to pond. Some of the water would make its way through the gravel most would flow over the top. I had a set up like that before, it did not work that well.
The piping distributes the water under the pea gravel. It has only one way to go up and through the gravel to get back into the pond. I used pea gravel due to the size, surface area.
I check the distribution by digging a small basin here and there in the bog to see if it fills with water from below.

At this time I am totally pleased with how my water looks, this is the 5 foot area, I took the shot focused on the obedience flowers for someone more than for the water or fish. The rocks towards the top fell in last year, one of these days I will get them out, that edge is around 15 feet from where I was standing.

 

[Waterbug]

Like in quantum theory where the act of observing an event changes the event the act of digging a hole to watch water flow changes that water flow. And to be fair Addy you have also said your bog made water cleaner than your drinking water and zero DOCs. Looking at stuff, formulating a theory and then jumping that theory directly to fact is going to be problematic.

But hey, no big deal here. People can add all the distribution pipes they like, drill holes as much as they like, I don't think it will really have any affect on bog performance. Certainly no data to show pipe matter at all. That's the beauty of bogs, they're almost bullet proof. A bog operating at even 20% of capacity is still fine. If performance was an actual concern there are way better filters for handling those concerns. But like I said, I wouldn't stress over hole sizes, placement, etc. Doesn't really affect anything.

 

[crsublette]

Wicking and travelling through capilary action is what will allow the water to penetrate most of the bog, but there will likely be areas where there is more of a high water flow area, that is creating a channelling effect, whether it occurs in the gravel or at the surface area with any implementation.

I would not go so far to suggest the placement and size of slits and holes are irrelevant since it should be done in a way to prevent blockage. Otherwise, if not done correctly, then I can see how clogged slits/holes will significantly reduce the water flow and increase the systems head height demand. It all depends on how much flow the owner wants to see through the bog. If it is just going to be a gravity flow and the bog is built like a wicking bed, then the placement and size of the slits/holes would be relevant only to the extent that bog medium does not go into the pipe, but, if the owner wants a much higher flow rate, then placement definitely will become quite relevant.

Personally, I would approach the pipe installation as it is done in an aquaponic wicking bed construction.

I like Addy's suggestion in her post#13. Although, I would make an upgrade to it.

After the distribution pipe is placed, then pile up 1~2" smooth river rock all around the distribution pipe and then a very thin, quite porous weed material (or something like it) over the smooth river rock. The river rock will create plenty of big caverns and area for the water to exit the distribution pipe while the material over it will prevent any small gravel medium or muck from easily entering the distribution pipe. This is a quite simplified approach of how an aquaponic wicking bed is built, but this will allow the bog to have a much higher flow rate than a typical wicking bed.

 

[addy1]

I would be concerned about having weed material, unless it is real porous. I used some in a skippy type filter, it clogged up quickly, that was shade fabric which is porous. Like the idea of river rock or large gravel around the pipe, but no way digging mine out to change ............lol
The one reason I placed my slits down was to keep any muck, pea gravel shifting, from plugging up the outflows.

I needed enough flow to handle a pump that would cycle my pond decently. Also wanted a nice waterfall back into the pond. We are using a 6800 gph pump with 2 outflows to other objects besides the bog now. All controlled outflows, one to the subunkin tank, 2 inch pvc with a ball valve, one to the small preforms via a garden hose and a 3/4 faucet.

We started out with a pump that did around 2400 gph until my dragon pumps got shipped here from my house in arizona.

 

[crsublette]

I would be concerned about having weed material, unless it is real porous. I used some in a skippy type filter, it clogged up quickly, that was shade fabric which is porous. Like the idea of river rock or large gravel around the pipe, but no way digging mine out to change ............lol
The one reason I placed my slits down was to keep any muck, pea gravel shifting, from plugging up the outflows.

I needed enough flow to handle a pump that would cycle my pond decently. Also wanted a nice waterfall back into the pond. We are using a 6800 gph pump with 2 outflows to other objects besides the bog now. All controlled outflows, one to the subunkin tank, 2 inch pvc with a ball valve, one to the small preforms via a garden hose and a 3/4 faucet.

We started out with a pump that did around 2400 gph until my dragon pumps got shipped here from my house in arizona.

Yeah, after I thought about it more, I tend to agree with ya.

Also, not for sure if mentioned before, I would encourage to do some type of pre-filter so that twigs or leaves and stuff do not get pushed into the distribution pipe.

In a true low flow wicking bed, I think the weed material works since the flow rate is quite low in these systems, but the weed material may likely add too much restriction when doing a higher flow rate.

 

[addy1]

I draw a foot off the pond bottom and have a huge leaf basket before the pump (external pump) No large debris can get into my pipes. That was part of my planning.

 

[Stouty109]

Alright ill get pic up soon of my pond in progress so yall can get a idea of what I have goin on. Thanks much for the input.

 

[Waterbug]

Wicking and travelling through capilary action is what will allow the water to penetrate most of the bog, but there will likely be areas where there is more of a high water flow area, that is creating a channelling effect, whether it occurs in the gravel or at the surface area with any implementation.

Capilary action in a bog is virtually non-existent. 99.999999999% of water movement thru a bog is good old gravity.

 

[crsublette]

Capilary action in a bog is virtually non-existent. 99.999999999% of water movement thru a bog is good old gravity.

Fair enough correction, depending on the force of water flow and the location of the bog's outlet.

 

[brokensword]

When I was considering filtration and such, I ran across Addy's thread and used that as the basis for my bog with input from another website. What I did was to dig down 3 feet and lay my 4" corrugated input drain pipe with the saw slits there. I used a chain saw for the cuts, which go halfway through the pipe, about every 4 inches of length. Total length of my bog pipe is about 5', gallonage about 300, dimensions 3'x4'x36" deep. Pond gallonage is about 2500, with the bog dropping water to a short, shallow river which drops its flow to the pond.

First layer of coverage was about a foot of 4-6" smooth river rock, followed by another foot or so of 2" river rock, then I filled the rest with pea gravel. At the pump, I have half inch plastic mesh surrounding my submersible pump to keep large debris from entering the system, and the pump sits a foot above the bottom. The pump sends the water to a falls and past, to the bottom of the bog for up-flow filtration.

Like Addy, haven't had any problems with the water clarity nor flow. The plants in the bog are larger than in the pond, so I'd assume the nutrients are being held and/or used primarily in the bog area. I have had some string algae but it tends to dissipate once full summer arrives. I'm crediting the plants and fish for lessening the algae.

Anyway, I'm glad I found Addy's thread and went this way as for 3 years now, I've had no maintenance re filtration and water conditions. For me, mimicking nature seemed both easiest and best.