Firstly, I appreciate all the help that has been provided to date.
My pond is app. 6,400 gallons and average depth of say 3 feet.
Originally I decided to add a nice 3 foot waterfall with a 4 foot wide and 30 foot long stream.
As I now realize a single 3 foot drop has splash issues I had not considered (thank you for the heads up, GBBUDD) I decided to go with a series of smaller drops to minimize splash and add interest.
As I am now obsessed with my new hobby I started reading more on the forum before picking up the shovel again.
I started to read about bog filters (elevated ,gravel upflow) and thought why not. In for a penny in for a pound.
Initial thought was place the bog ( in a plastic stock tank behind the waterfall but at same or slightly higher level to aid flow to spillway from stock tank. Am I correct that bog outflow cannot be lower than spillway or I will have possible bog overflow due to pressure?
If this is the case I may scrape the waterfall and just go with a nice stream or possibly a lower waterfall as elevating the bog to 3 feet on a foundation of compacted earth may look silly and present difficulties in accessing the bog for planting etc.
So I researched the heck out of bog filters planned out the plumbing (1.5 or 2 in pvc with slots in top every 4-6 inches, cap the ends and of course a clean out pipe just above gravel which would be capped. I would be using an 8 foot diameter 2 foot high stock tank with a drain plug. The bog itself would be no more than re recommended 12 inches deep. And I would use 3/8 pea gravel as a bed.
Of course I then read about dwell time which frankly makes little sense to me. I see dwell time in minutes which would necessitate a slow flow in the order perhaps hundreds as opposed to thousands of gallons an hour. My pump flow with calculated head pressure would be app. 3,000 GPH.
So now I'm thinking too fast for a bog so lets do the following, place the bog next to the waterfall and add a Y connector with ball valves. Now most of flow to waterfall and minimal flow to bog and let this "trickle" from the bog enter the pond directly. Of course if I go this route most of my water is not being filtered by the bog but rather feeding the waterfall !! So what was the point of building a bog?
So now really lost. As I understand it the beneficial bacteria only need contact time of seconds to convert products so not really sure where this dwell time of 6-8 minutes came from. Maybe I'm wrong but I would think greater flow is greater turnover which equates to better filtration.
Iwould bet there are upflow bogs with fast and with slow flow and possibly they both work.
FWIW: I currently have no filtration. None, nada. And believe it or not I can see the bottom of my pond ! Thank you, Mother Nature.
Look I do realize the bog would aid in the health of my pond but I can clearly do without it. I do not have KOI. Just a half dozen pet shop goldfish, some frogs,cattails and lots of water hyacinth (geat for filtering as I understand it.) I am in full sun and never had an issue with algae. Maybe I am just lucky. I live in north central Florida (Ocala) so I have more than my share of hot days and blistering sun but no algae. Go figure.
OK too long winded. Just need opinions on whether to have water flow from bog to waterfall at high flow rate or put in a Y connector and have bog flow SLOOOOW. Must outflow of bog be higher than the top of my waterfall ??
Also, do I NEED a clean out pipe if I do a bog. Couldn't I simply shut off the pump ( I will install a check valve to prevent dirty water from back flowing to pond) open the drain valve on the stock tank and let the muck drain out?)
Lastly, since koi are as I understand it are a form of carp which typically live in muddy water several feet deep why do koi afficianados ( and I respect their hobby) strive for crystal clear water? Is it a pride thing or just to better visualize the fish because honestly in my pond with NO current filtration I could for sure see koi if I were to stock them.
I appreciate all your past and future advice.
My pond is app. 6,400 gallons and average depth of say 3 feet.
Originally I decided to add a nice 3 foot waterfall with a 4 foot wide and 30 foot long stream.
As I now realize a single 3 foot drop has splash issues I had not considered (thank you for the heads up, GBBUDD) I decided to go with a series of smaller drops to minimize splash and add interest.
As I am now obsessed with my new hobby I started reading more on the forum before picking up the shovel again.
I started to read about bog filters (elevated ,gravel upflow) and thought why not. In for a penny in for a pound.
Initial thought was place the bog ( in a plastic stock tank behind the waterfall but at same or slightly higher level to aid flow to spillway from stock tank. Am I correct that bog outflow cannot be lower than spillway or I will have possible bog overflow due to pressure?
If this is the case I may scrape the waterfall and just go with a nice stream or possibly a lower waterfall as elevating the bog to 3 feet on a foundation of compacted earth may look silly and present difficulties in accessing the bog for planting etc.
So I researched the heck out of bog filters planned out the plumbing (1.5 or 2 in pvc with slots in top every 4-6 inches, cap the ends and of course a clean out pipe just above gravel which would be capped. I would be using an 8 foot diameter 2 foot high stock tank with a drain plug. The bog itself would be no more than re recommended 12 inches deep. And I would use 3/8 pea gravel as a bed.
Of course I then read about dwell time which frankly makes little sense to me. I see dwell time in minutes which would necessitate a slow flow in the order perhaps hundreds as opposed to thousands of gallons an hour. My pump flow with calculated head pressure would be app. 3,000 GPH.
So now I'm thinking too fast for a bog so lets do the following, place the bog next to the waterfall and add a Y connector with ball valves. Now most of flow to waterfall and minimal flow to bog and let this "trickle" from the bog enter the pond directly. Of course if I go this route most of my water is not being filtered by the bog but rather feeding the waterfall !! So what was the point of building a bog?
So now really lost. As I understand it the beneficial bacteria only need contact time of seconds to convert products so not really sure where this dwell time of 6-8 minutes came from. Maybe I'm wrong but I would think greater flow is greater turnover which equates to better filtration.
Iwould bet there are upflow bogs with fast and with slow flow and possibly they both work.
FWIW: I currently have no filtration. None, nada. And believe it or not I can see the bottom of my pond ! Thank you, Mother Nature.
Look I do realize the bog would aid in the health of my pond but I can clearly do without it. I do not have KOI. Just a half dozen pet shop goldfish, some frogs,cattails and lots of water hyacinth (geat for filtering as I understand it.) I am in full sun and never had an issue with algae. Maybe I am just lucky. I live in north central Florida (Ocala) so I have more than my share of hot days and blistering sun but no algae. Go figure.
OK too long winded. Just need opinions on whether to have water flow from bog to waterfall at high flow rate or put in a Y connector and have bog flow SLOOOOW. Must outflow of bog be higher than the top of my waterfall ??
Also, do I NEED a clean out pipe if I do a bog. Couldn't I simply shut off the pump ( I will install a check valve to prevent dirty water from back flowing to pond) open the drain valve on the stock tank and let the muck drain out?)
Lastly, since koi are as I understand it are a form of carp which typically live in muddy water several feet deep why do koi afficianados ( and I respect their hobby) strive for crystal clear water? Is it a pride thing or just to better visualize the fish because honestly in my pond with NO current filtration I could for sure see koi if I were to stock them.
I appreciate all your past and future advice.
Last edited: