New pond design.

Discussion in 'Pond Construction & Equipment' started by Peter B, May 19, 2014.

  1. Peter B

    Peter B

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    Hello,

    I am considering building a new raised koi pond in my backyard. I had a koi pond about 8 years back. Due to some bad information the pond wound up being very small (~300 gallons). It was over stocked and required constant maintenance to make sure the fish stayed happy and healthy. Eventually I moved and could not take the pond with me.

    Now I have an opportunity to build a new pond, and wanted to get some feedback. The plan is build a 16x4 rectangular shape. The depth will be 3-4 ft deep. 1-2 feet will be raised, and the rest will be dug into the ground. I'm shooting for somewhere in the neighborhood of 1200-1500 gallons. At each end I will build another 4x4x1.5 box. One will be a hi-flow waterfall, the other will be a low flow "swamp filter". My first question is about the frost line. I live in central MA and the general rule is to go 36" deep to avoid freezing (48" for footings and walls). However this winter, which was colder than most, the frost line was recorded at only 18". My previous pond was only 32-34" in the very center and it never froze deeper than 5-6 inches down. How deep do most people build their ponds in the northeast? How deep have people seen their ponds freeze? A few people have suggested that 24" down would be sufficient to prevent freezing. Thoughts?

    I was also wondering how a raised pond works in colder climates. I spoke with a gentleman and a local pond supply store. They had a pond that was 8x4x4 100% above ground and he told me it didn't freeze completely or suffer other ill effects this past winter.

    For my pump and filtration system I am going to use a Laguna Max Flo 2400 (2400 gpm @ 0' head) pump, and pressurized canister filter(probably). I have had good luck with Laguna and they are some of the most efficient pumps on the market, so the cost to run won't be as high. I was going to oversize the filter and try to find something for a pond in the 2500-3500 gallon range. I was planning on purchasing a filter that included a UV light in the 18-24 watt range. My experience keeping fish is that an oversized filter is usually a good thing. My last pond the filter was only slightly oversized and required constant cleaning and work. I would like to avoid that this time. Any advice on filters would be greatly appreciated. I like the Laguna brands, but they are very expensive and I am on a tight budget.

    For the liner I plan to purchase a 25 x 15 rubber (not pvc) 45 mil liner. I will put sand at the bottom of the hole, and padding under the rubber liner to protect it from punctures.
    My original plan was to build the whole thing out of 4x4 pressure treated posts. However this option is looking very expensive. I priced it out at $700+ for all the posts. My other option is to use 2x6s and brace them with 4x4 posts every 4 feet or so. Pricing it out this way I came up with a total cost of about $402. If anyone has any thoughts on how to do this please feel free to share. My constraints are the following. Budget is the biggest. I need to keep my costs as low as possible. Space is tight, as my backyard is small. Depth-- it will be easier for me to raise the pond up, than it will to sink it down. Any thoughts, advise, etc would be greatly appreciated.

    Pete
     
    Peter B, May 19, 2014
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  2. Peter B

    Peter B

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    *Bump* Anyone?
     
    Peter B, May 29, 2014
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  3. Peter B

    pecan

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    Hello!

    A few things to consider if you plan on keeping koi is they need a minimum of 36" depth and 1000 gallons min volume, plus 500 gallons per additional koi. So 1500 gallons equals 2 koi. 10 tiny koi may be fine for a few years but they grow fast and are poop machines.

    That is a general rule of course and extra filtration and maintenance (water changes more often), which it sounds like you are trying to avoid, can allow for more fish in less water. If you build an environment "healthy" for koi then I don't think the freezing is a consideration as much since it should already be deep enough.

    As far as freezing, I live in zone 7, our temps get to 0 at the lowest and my pond (3 years old) has frozen down to about 12". I have heard horror stories of folks who went 2' deep and their ponds were fine until a once in 20 year winter froze their pond solid killing everything.

    If you do a raised pond I would consider using pink foam insulation sheets under the liner and maybe even build a temporary cover over it in the winter for a sort of green house effect.
     
    pecan, May 29, 2014
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  4. Peter B

    Peter B

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    500 gallons is much higher then anyone has ever suggest before. Most of what I have read, or been told is ~250-350 gallons per koi. Is 500 really the number?

    As for the pink foam insulation and cover, that is a good idea. Several people have suggested it and I think I will do it.

    Pete
     
    Peter B, Jun 4, 2014
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  5. Peter B

    CountryEscape

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    The number of koi and number of gallons is more about maintenance and how you plan to filter it, than number of gallons per koi, IMO. Pecan is right, if you filter and do water changes, etc. you can get away with more fish. I have 4200-45000 gal pond plus a large bog (another 300 gal or so) but too many koi, so I'm not a good judge. LOL My goldfish pond is 2700 gal, plus a HUGE bog (another 600 gal) and about the same inches of goldfish as koi, and that pond is crystal clear. Going to increase my plant bog in the koi pond and see if that does the trick.
    I live in south/central IL, we had HORRENDOUS winter, too, and electricity went off for 24 hours. Ponds both froze, but neither of them ever got more than I'd guess 5-6" of ice. My koi pond (bigger) is 12" above ground, 4' deepest, 3' deep other half, and goldfish pond is partially above ground about 12" also, but that side has a bog all along it. I kept bog pump running all winter and skimmers as long as there was free flowing water in front of them, and that kept water circulation, thus less ice. Also kept a small fountain pump about 18" below the water surface blowing the water towards the ice, which did a great job of keeping an opening in the ice, and air bubbler in koi pond did the same thing. I was testing to see which was better.
     
    CountryEscape, Jun 4, 2014
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