GPH for Bog Filter..?

[addy1]

How often is it necessary to empty these leaf baskets during leaf drop season (Fall)?

Very seldom, The trees are down wind of the ponds, the majority blow out into the back field, our winds have a definite west to east flow. I do empty it a lot when the maple spinners are falling, that and the apple blossoms.

 

[Meyer Jordan]

Very seldom, The trees are down wind of the ponds, the majority blow out into the back field, our winds have a definite west to east flow. I do empty it a lot when the maple spinners are falling, that and the apple blossoms.

That 's great. Overall you appear to have a very low amount of allochthonous (external organic) material entering your pond. This surely is a major factor in your "bog" not clogging. What little that you are getting is not sufficient to cause an issue. Even though the cellulose in this debris may take days to weeks to fully breakdown, its effects are minimal. Your "bog" size also plays a huge role.

 

[addy1]

That 's great. Overall you appear to have a very low amount of allochthonous (external organic) material entering your pond. This surely is a major factor in your "bog" not clogging. What little that you are getting is not sufficient to cause an issue. Even though the cellulose in this debris may take days to weeks to fully breakdown, its effects are minimal. Your "bog" size also plays a huge role.

I sort of planned it that way, sort of. Watched the main wind direction, put the skimmer down wind, put the waterfalls up wind. Crossed fingers during the first leaf fall. It worked. The size was mainly due to wanting a lot of plants growing. And someone that was digging it just made it that big! i.e. me lol
My biggest bio load is dropping apples, but they float and I just pull them out.

 

[Mucky_Waters]

No, science wins. All I did was relay information.

Well not necessarily. Your "science" suggests that dwell time should be greater than 24 hrs to function properly, and I'm betting Addy's bog is getting no where near that long of dwell times in her bog, and yet her's seems to be functioning just fine.

I found this guideline:
"Mungasavalli et al. (2006) suggested retention time should be greater than 24 hrs.."

Addy, perhaps you could tell us the approx size of your bog and your flow rate so we could calculate what your dwell time is.

 

[Meyer Jordan]

Well not necessarily. Your "science" suggests that dwell time should be greater than 24 hrs to function properly, and I'm betting Addy's bog is getting no where near that long of dwell times in her bog, and yet her's seems to be functioning just fine.

Addy, perhaps you could tell us the approx size of your bog and your flow rate so we could calculate what your dwell time is.

Randy, those guidelines would not necessarily apply to Addy's "Bog" as this is her primary biofiltration. Those guidelines are for wetlands filters that are used as engineered....for secondary (sometimes tertiary) filtration to remove nutrients and pollutants only.
Addy's "bog" will supply these 'polishing' processes, but not to the same level of efficiency as a "bog" used as secondary filtration.

 

[addy1]

Well not necessarily. Your "science" suggests that dwell time should be greater than 24 hrs to function properly, and I'm betting Addy's bog is getting no where near that long of dwell times in her bog, and yet her's seems to be functioning just fine.

Addy, perhaps you could tell us the approx size of your bog and your flow rate so we could calculate what your dwell time is.

Mine is not built like a wet lands filter, it is more like a up flow pea gravel filter. Full of plants. My pump runs 6800 gph minus head pressure, minus a bit that goes to the other pond. I don't fit into a wetlands filter scenario.

 

[Meyer Jordan]

Mine is not built like a wet lands filter, it is more like a up flow pea gravel filter. Full of plants. My pump runs 6800 gph minus head pressure, minus a bit that goes to the other pond. I don't fit into a wetlands filter scenario.

There are two (2)configurations for engineered wetlands: Surface flow and Sub-surface flow. Your "bog" is a variation of the Sub-surface flow design, but because of your flow rate is more of a biofilter than a phyto-filter thus, as you say, not really a true wetlands filter.

 

[addy1]

Addy, perhaps you could tell us the approx size of your bog and your flow rate so we could calculate what your dwell time is.

Forgot the size. It is around 26 feet long, 4.5 feet wide, 2.5 feet deep. Waterfalls back into the pond.

 

[Mucky_Waters]

Randy, those guidelines would not necessarily apply to Addy's "Bog" as this is her primary biofiltration. Those guidelines are for wetlands filters that are used as engineered....for secondary (sometimes tertiary) filtration to remove nutrients and pollutants only.
Addy's "bog" will supply these 'polishing' processes, but not to the same level of efficiency as a "bog" used as secondary filtration.

So what is the difference between Addy's bog, and the OP's bog that you were originally applying those wetland guidelines to? This is how we got on the topic in the first place.
To reiterate: You stated that the OP's water flow through their bog was too high, and when I asked how you determine that and what you were basing it on you brought up "wetland filters" guidelines. Now when we are trying to determine the flow in Addy's bog you excuse it and say "wetlands filter" guidelines don't apply because her bog is really not a true wetlands filter, and yet, she has basically the same type of "bog" as the OP.

 

[Meyer Jordan]

Will 1700ish gph be to fast water for my bog plants? I have cat tails, pickerel rush, lillies in the filter.

This is the OP's original question. Based on the fact that the question was focused on the plants and not the "bog" proper, It is assumed that they are concerned about the ability of the plants to efficiently filter the water. The answer remains the same. At 1700 gph, the rate of nutrient uptake for the plants will be limited in that size 'bog".

 

[Stephen T.]

Just in terms of bog plants and their uptake of nutrients, how does flow rate affect them? A bog using pea gravel seems like it would be very similar to some organic hydroponic gardening techniques.

 

[Mucky_Waters]

I believe Addy's bog utilizes plant nutrient uptake as well.
Anyway, I'm following your logic a little better now, however, I still think a one pass wetlands filter is an inappropriate guideline to apply on a recirculating bog system. When a biological filter is employed in a recirculating system we don't expect all nitrogen conversion to happen in one pass. Nor does it makes sense for us to expect the plants to have to absorb all the nutrient in the water in one pass in a recirculating bog system. Perhaps some sort of recirculating hydroponic system would have more appropriate guideline for dwell times for the most efficient nutrient uptake.

 

[Mucky_Waters]

Just in terms of bog plants and their uptake of nutrients, how does flow rate affect them? A bog using pea gravel seems like it would be very similar to some organic hydroponic gardening techniques.

Ha, you posted at the same time I did. I think we are on the same page here.

 

[Meyer Jordan]

I am not all that knowledgeable on aquaponic/hydroponics, but if one wants to compare a pond to an aquaponics system, a couple of things need to be mentioned. First is the ratio of grow bed size to fish tank size. It seems that the accepted norm is 1 to 1 (equal size), some advocate that the grow bed be twice the capacity of the fish tank. Secondly, most flow rate recommendations that I have read are 5 - 10 gpm. Just these two (2) differences are enough to suggest that a low flow rate is preferable in aquaponics/hydroponics.

 

[Mucky_Waters]

I am not all that knowledgeable on aquaponic/hydroponics, but if one wants to compare a pond to an aquaponics system, a couple of things need to be mentioned. First is the ratio of grow bed size to fish tank size. It seems that the accepted norm is 1 to 1 (equal size), some advocate that the grow bed be twice the capacity of the fish tank. Secondly, most flow rate recommendations that I have read are 5 - 10 gpm. Just these two (2) differences are enough to suggest that a low flow rate is preferable in aquaponics/hydroponics.

What I'm reading is your 1 to 1 ratio (equal size) for grow bed and fish tanks size is correct, but I'm also reading that you should be cycling, or turning over, the water every hour minimum. So a flow rate for a 100 gallon grow tank should be 100 gph. Pretty much the same as what is recommended for standard ponds. I'm not sure how you came up with 5-10 gpm? That would work for a 300 growing tank, but it would be below the recommended flow rate for anything bigger.