Small Mud Pond --> What type of mud ?

[kevhuynh]

What is the minimum size and type of mud to use for an effective mud pond ?Any koi hobbyist have one in their back yard ?

Kevin

[bekko]

Mud ponds work best when the feed rate is only about 2 grams per square meter per day. With good aeration, the maximum for koi is probably about 5 grams of feed per square meter per day. So, figure the total weight of the fish, multiply by 1.5% per day feed rate, divide by 2 (up to a maximum of 5) to get the area in square meters. Multiply meters by 10.8 to get square feet.

Example:
two 24-inch fish weighing 8 pounds each = 3,256 grams
7,256 grams x 1.5%/day fed = 109 grams feed per day
109 grams divided by about 2 = 55 square meters = 585 square feet =
about 24 feet x 24 ft
or:
109 grams divided by 5 grams per square meter = 22 square meters = 234 square feet = about 15 ft x 15 ft

Despite the name and the dogma, mud ponds seem to work best when the soil is a little sandy and the pond leaks a little. It makes for a more robust benthic community and forces water renewal. That said, unless you have a lot of free water, you look for very tight clay soils to build in.

-steve hopkins

[Dwight]

What about the type of clay ? Does the water source have as large ab effect as it does in a " show " pond ?

[bekko]

The cat clays in low-lying coastal areas can be problematic because of the acid sulfate reaction. In Texas there is a lot of alkaline clay which requires some special care. Best thing is to go to your nearest US Soil Conservation Service office and look up the soil type for your location, then read the soil type description. The soil type description probably tells you everything you need to know. Some of the SCS guys are really savy about pond construction as well.

The water source and soils interact to make the pond water quality what it is. A little research on the soil type and water source will provide insight into whether or not you are likely to end up with some weird pond water quality. However, its pretty unusual to find a water source and soil type combination which will not grow fish. Sure water quality affects the fish. However, the very low fish density and the availability of natural forage makes a mud pond much more forgiving than the typical backyard koi reactor. That natural forage works wonders for grazers like koi..

-steve hopkins

[jbolding]

I have also often tossed around the idea of putting a small mud pond (20x60x4) is my back yard. The questions that always seem to shoot it down for me are soil quality (and even once I know the quality how do I know it's rick for my fish), cost of water (after being filteredfrom water source) lost do to the soils potenial lack of water rentention, and stocking levels for this pond. So Steve if I went to US Soil Conservation Service should they be able to help me with some of these issues?

[bekko]

SCS can definitely help, but I just realized they had a name change to Natural Resource Conservation Service. A lot of the soil maps are on the web now. Check this out.
http://soils.usda.gov/

The quick-and-dirty soil test is to roll of ball of in between your hands and then drop it on the ground. If the ball does not fall apart, there is probably enough clay to build a pond.

If your only water source is from the tap [mains], you may have a problem. Normal seepage could cost you a fortune.

Some of the best ponds are lined ponds which have an overlay of sand or loam on the bottom. You get the best of both worlds - robust benthic community and no seepage.

See info above about stocking levels. If you are going to overload the pond, it will not work.

-steve