Minimum Pond Circulation

Discussion in 'Water Features' started by Gordnovo, Jun 15, 2007.

  1. Gordnovo

    Gordnovo LawnSite Member
    Posts: 1

    Hello,

    Hello everyone, I'm a homeowner who's been experimenting with pond building over the last couple of months and I've been doing a fair amount of investigating on what I need to do to make our pond dreams a reality.

    I've attached a picture of our pond from a week ago. The water level has since been raise by another 9" and we have a fair amount of wood chippings down on either side of the sandy beach.

    I've got a lot of questions based on my investigations so far. I seem to get a lot of conflicting answers from different people who want to sell us products to help keep our pond fresh. What I'm looking for is some objective suggestions. Any insight or info anyone can share would be greatly appreciated.....thanks!!



    Q1. Will two 2000 GPH pumps streaming a 6-8 ft high bead of water to the center of either end be enough to aerate the pond and maintain adequate "good bacteria" levels? I've heard people say that the water should be circulated entirely every two hours. This doesn't seem possible with a pond our size.

    Q2 Will these two pumps be sufficient to control mosquito growth? I have a temporary 1/2 horse sump doing the circulating for us right now and it seems to create a fair amount of dimpling of the surface. So I'm hoping this will work for us.

    Q3. Is the water safe for the kids to swim in?

    Q4. Should I look into some kind of support material on the banks to prevent them from caving in over time? My worry is the winter freezing will crumble the walls.

    Q.5 Should I empty the pond in the fall time (just before the snow) or should I ensure it's completely filled?

    Q6 How many gold fish is too many? Would you recommend stocking with 10, 20, 40, 80 ... goldfish? I know they can help with keeping the mosquito larvae down.



    here are some specs to help describe what we have and how we want to use it:

    • I dug it out last month, and have been slowly filling it with water. (man, it took a while to fill!)
    • It's kidney bean shaped.
    • 3 - 3.5' deep
    • 65 fee long, 25' wide at the widest points
    • By my calculations, it's approx 40,000 gallons
    • The banks are fairly steep on the edges (except where the beach is) so I'm hoping it won't cave in.
    • One side has a gradual slope with a sand beach (with a heavy duty tarp below it)
    • There is no rubber liner at this point, instead we have a natural clay lining throughout. This pond doesn't really loose water.. it's been at 3' now for over a weeks since I filled it.
    • will house some small fish, goldfish primarily (but fish are not a real priority). They'll be left in over winter and scooped out the following spring if we find them. Our winters are very cold here in Canada (-40C) in January, so I expect the pond the freeze completely.
    • The Pond will primarily be used by the kids in summer to go wading and to cool off from the hot days.
    • Plus we'd like to plant some perennial vegetation that'll help give it a real natural look. Pond lillies, reeds, etc.
    • I builit a burm around the perimeter of the pond to prevent lawn runoff from the heavy rains.

    Pond.jpg
     
  2. Victor

    Victor LawnSite Bronze Member
    Posts: 1,430

    Gordnovo... Hello everyone, I'm a homeowner who's been experimenting with pond building over the last couple of months and I've been doing a fair amount of investigating on what I need to do to make our pond dreams a reality.

    I've attached a picture of our pond from a week ago. The water level has since been raise by another 9" and we have a fair amount of wood chippings down on either side of the sandy beach.

    I've got a lot of questions based on my investigations so far. I seem to get a lot of conflicting answers from different people who want to sell us products to help keep our pond fresh. What I'm looking for is some objective suggestions. Any insight or info anyone can share would be greatly appreciated.....thanks!!



    Gordnovo...Q1. Will two 2000 GPH pumps streaming a 6-8 ft high bead of water to the center of either end be enough to aerate the pond and maintain adequate "good bacteria" levels? I've heard people say that the water should be circulated entirely every two hours. This doesn't seem possible with a pond our size.

    Victor...No. They won't be big enough to come close to providing enough circulation to properly filter this pond. They should help to aerate it a little, but asking such little pumps to deal with 6-8 feet of head, will end up giving you minimal flow out of your waterfall weirs. Not good.

    Gordnovo...Q2 Will these two pumps be sufficient to control mosquito growth? I have a temporary 1/2 horse sump doing the circulating for us right now and it seems to create a fair amount of dimpling of the surface. So I'm hoping this will work for us.

    Victor...I doubt that those two little pumps will stop wigglers from showing up (especially when you consider what I told you about the 6-8 feet of head you're going to ask them to overcome)..

    Gordnovo...Q3. Is the water safe for the kids to swim in?

    Victor...Your water's going to get really nasty if you set your pond up the way you mentioned in this thread. I wouldn't let my kids swim in there. You will have a lot of pathogens in there.

    Gordnovo...Q4. Should I look into some kind of support material on the banks to prevent them from caving in over time? My worry is the winter freezing will crumble the walls.

    Victor...It's hard to tell exactly how steep your walls are, so it's impossible to make a judgment call on this one. You might have some problems with your banks giving way if you made them too steep.

    Gordnovo...Q.5 Should I empty the pond in the fall time (just before the snow) or should I ensure it's completely filled?

    Victor...Once the pond is filled, leave it that way. If you empty it, you'll lose any beneficial nitrifying bacteria that's in the pond. That means your bacteria colony would have to establish itself, all over again when you refilled it the next year. Not good.

    Gordnovo...Q6 How many gold fish is too many? Would you recommend stocking with 10, 20, 40, 80 ... goldfish? I know they can help with keeping the mosquito larvae down.

    Victor...Start off small (say 10 goldfish) and let them seek their own level. If you put just a few fish in your pond, they will multiply until their numbers have reached what your pond will support. Let mother nature handle this for you.

    Gordnovo...here are some specs to help describe what we have and how we want to use it:


    Gordnovo...I dug it out last month, and have been slowly filling it with water. (man, it took a while to fill!)
    It's kidney bean shaped.
    3 - 3.5' deep
    65 fee long, 25' wide at the widest points
    By my calculations, it's approx 40,000 gallons
    The banks are fairly steep on the edges (except where the beach is) so I'm hoping it won't cave in.
    One side has a gradual slope with a sand beach (with a heavy duty tarp below it)
    There is no rubber liner at this point, instead we have a natural clay lining throughout. This pond doesn't really loose water.. it's been at 3' now for over a weeks since I filled it.
    will house some small fish, goldfish primarily (but fish are not a real priority). They'll be left in over winter and scooped out the following spring if we find them. Our winters are very cold here in Canada (-40C) in January, so I expect the pond the freeze completely.

    Gordnovo...The Pond will primarily be used by the kids in summer to go wading and to cool off from the hot days.

    Gordnovo...Plus we'd like to plant some perennial vegetation that'll help give it a real natural look. Pond lillies, reeds, etc.

    Gordnovo...I builit a burm around the perimeter of the pond to prevent lawn runoff from the heavy rains.


    Victor...About the best advice I could give you, would be to plant lotus in your pond. They're heavy feeders and in time, will establish themselves to the point where they'll keep your water clean and clear for you. That way, you won't have to rely on a filtration system. As the one you mentioned is woefully inadequate.
     
  3. Nobletoad

    Nobletoad LawnSite Member
    Posts: 8

    You might also want to consider getting some mosquito fish, Gambusia affinis. They are a smallish species, kinda like a minnow. They don't detract from the look of the pond, they are largely inconspicuous and they devastate mosquito larvae populations way beyond what goldfish will do. Check with your local authorities to see about their availability in your state. In Florida, you can actually get them directly from the vector control office as they are considered to be an effective mosquito preventative in keeping down mosquito-bourne diseases.

    95007021.JPG
     
  4. Mr. Vern

    Mr. Vern LawnSite Senior Member
    Posts: 632

    Mosquito fish are very effective at clearing mosquito larvae, but beware that they will eat your fish eggs ravenously. If you intend to let the goldfish population expand, you might not want the mosquito fish.
     
  5. Nobletoad

    Nobletoad LawnSite Member
    Posts: 8

    Mr. Vern is absolutely correct. If you intend to have other fish breeding in the pond, then mosquito fish will not discriminate between mosquito larvae, fish eggs or even small fry. They play nice with any fish beyond the fry stage, but I'd exercise caution if you're planning to breed the goldfish. I hadn't originally considered this since I used them in Tilapia ponds. Tilapia are mouthbrooders and the adults defend the eggs and fry vigorously so it was never an issue.
     

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