What's the minimum depth for a bog?

[Mmathis]

And can you run air through the gravel?

 

[addy1]

6-12 inches and yes
I would stick with 12 inches deep

 

[Waterbug]

There's very little info on how a bog works or any data on what different depths do or don't do. If you looked at what most people post they made their depths it would be in the 12-18" range, sometimes deeper.

If you looked at it from the perspective of what you wanted to accomplish I think you could consider different depths. For example if your primary goal was to filter particles out of the water I'd say the deeper the better, so like 18-24". That would reduce the times needed between clean outs. On the other hand if your goal was ammonia/nitrite conversion and/or no build up of waste and harmful Aeromonas bacteria, or future DOC build up then I think you'd want to consider a shallow and narrow bed maybe 2-4" deep which would be easier to clean more often. But like I said, no way to predict how different depths would actually perform in your pond.

 

[don't ask]

interesting question TM...Addy do you know or anyone else if it is somewhat common to run air for a bog? and would it be done just like the bog as in some 1/4 inch pvc pipe with lots of holes and a pump connected to that?

 

[Mmathis]

Just curious [depth & air], as I had an idea I might try with the turtle side of my pond. Have been filling in the "shore" area and out about 1/2 way with pea gravel. It looks like a very-mini bog, so I then started sticking little plants (mint, parrots feather, and a few others) in the pea gravel. It looks great, whether it "bogs" or not, who knows, but the turtles seem to like their bog-beach better than the stacked rock. It's probably only a few inches deep, and is basically bottomless since it sits on the false floor. Had always planned to divert some of the pump outflow to go under the turtle part just to be sure there was adequate current to wash out their waste. Was curious about adding the aeration to be under the turt part instead of water (will be easier to accomplish the air at this point... ).

Just another idea to work on Ya know how one idea leads to another, and another, and so on.

 

[Mmathis]

Forgot to add: One thing I wondered about air vs pumped water, is if the air would be as efficient at transporting nutrients to the roots. I know with garden plants, when you plant, you're supposed to smash the dirt around the roots really good. Have always believed this was to eliminate air pockets -- air pockets keep the roots from contacting the soil, which they need to do to be able to absorb water & nutrients. This is a possible "minus" for the air idea, however. Any thoughts?

 

[crsublette]

Yeah, planting in soil is different than planting in a bog. Firm soil encourages root branching and get more horizontal, shallow root growth wheree more nutrients reside from fertilizers. However, soil too firm will prevent deep root growth from capturing deep moisture; deep moisture is how plants survive drought and heat waves.

Plants going yellow and dieing in water saturated soil due to roots unable to cope with less oxygen and nutrients leaching.

Some plants are more adapt to having less oxygen available to their roots.

This has been my experience from farming. I bet a little different for bogs where the "soil" is always water saturated and always refreshed with some volume of nutrients and oxygen. I bet pumping more oxygen into the soil will help. If ya look into hydroponics, only some of the root zone is completely saturated in water.

 

[taherrmann4]

[quote name='don't ask' timestamp='1342635012' post='131347']
interesting question TM...Addy do you know or anyone else if it is somewhat common to run air for a bog? and would it be done just like the bog as in some 1/4 inch pvc pipe with lots of holes and a pump connected to that?
[/quote]

I was thinking you could do a diy venturi.

 

[brandonsdad02]

My bog is 18" deep at its deepest point and gets shallower from there. Where the bog flows back into the pond the bog is about 8"s deep. I think the air would only help things, but I could be wrong.

 

[addy1]

Mine is around 2.5 feet deep, some crazy person kept digging with a tractor until it was that deep. I have read that adding air will help the good bacteria, which likes air. My plants do fine without added air, just what is pumped into the bog. They grow like weeds and are very healthy.

If you read about building bogs the recommenced depth is 12-18 deep.

 

[brokensword]

After doing some research, including addy's bog thread, I made mine 40" deep, piling larger rocks first and working my way up to medium size and then to about 24" of pea gravel. I worried it wasn't really large enough, but the total volume is within the suggested 10% pond volume. Works a charm and is the only filtration system I have.

 

[Mmathis]

Another thought, is there anywhere in the "calculations" for a bog that actually covers the consideration of # and or % of plants? Since the function of a bog is dependent on the presence of plants, how many little rootlets [] are needed to make it functional?

Again, what I'm doing in the turtle section [a few square feet of gravel, 3 or so inches deep, with lots of little plants stuck in, sprouting roots] is not a bog, but it's got to be doing some good just by being there, right? There is good water flow via an overhead spray bar, and when I occas. stir up some gravel, there's hardly any sediment -- it stirs clean. Now, since the turts aren't fully utilizing their "facilities" yet, any waste products are coming from the water itself (spray bar water comes directly from the pump), and anything the goldies and/or "toad"poles are leaving behind. The plants are looking good.

Really, just curious as all I've read about bogs covers the % of the pond surface they should cover, but not the amt. of plants required. Food for thought [pun intended!]?

 

[HARO]

TM;
Have you ever seen plants advertised as 'indoor air cleaners' or some such designation? The idea is that these plants will help to remove contaminants from the air in your house. You don't need to FILL the house with them; a single spider plant hanging in a window will have SOME effect on air quality. I know you're wondering what this has to do with your bog, so I'll get right to it! One or two plants in gravel (or whatever) will still help to improve the water quality of the pond; You don't have to fFILL the pond with them. A small bog with a few plants is still better than nothing at all! :twocents:
John

 

[capewind]

Our bog is still under construction in the regard that it still needs a lot more gravel added (lots of rinsing first LOL) and needs more plants. Ours is dug more like a pond in the regards that it has "plant shelves" as well as "deep spots"... The plant shelves are only a bit better than a foot deep (done this way due to the pond sitting 7' above grade with limited backfill space available for now), the "shallow end" is about 24" and the "deep end" is EITHER 30 or 36" (I cant remember how deep he went LOL). To have the flow we want/need going into the pond (via waterfall, and to keep up with what we had on hand for a pump/8,000 gph), our gravel also sits about 2" below the water surface. A lot of people allow the top of the gravel to be dry. The "deep end" FOR NOW, only has a few inches of gravel, so that the lilies have a home for the time being, until we get the other pond built next year. We also have a grid of pvc piping with holes drilled in it, buried under the gravel ... I am taking the view that every plant helps the fish, but my reality is we like plants, and wanted a place to FILL with water loving plants... killing two birds with one stone so to speak.

 

[addy1]

I have some wet some dry gravel and tons of plants, one of the main reasons for the bog was the plants. Love the colors and flowers we get.
Love how well it takes care of the pond with minimal care.