Koi pond depth

[Steve]

Probably in the next 3-4 weeks I'll be helping my sister/brother in law dig a new Koi pond in their backyard. They don't have a ton of room so probably be on the order size wise of around 8ft x 4ft. Been doing some Googling to find depths but seeing a lot of different answers to this question. For here in SE Mi what would be a good depth to make the pond to give the koi the best winter survival?

[lightaddict08]

I have also been researching this and found varying results. The most common thing i have found is it will likely freeze about 18 inches down. I have in my plans to go 3 feet down as a safety factor. I have an in ground pool that gets drained halfway for the winter to be about 2.5 ft and last year it was frozen solid, but this year it didn't. If you get a heater you can go shallower. Just make sure there is still a way for oxygen exchange. Also make sure the edges are sloped so when it freezes the ice pushes up and not out.

[danielratti]

3 ft is best so it will not freeze all the way in the winter.  I'd still run a air pump to get a open area as well

[Steve]

Also make sure the edges are sloped so when it freezes the ice pushes up and not out

I didn't know about that. About how much of a distance should the slope cover, just 6" or so alright?

[lightaddict08]

You shouldn't have any vertical walls. I would recommend always putting a slight angle on it. It doesn't have to be far from vertical but just give the ice room to be pushed up.

[54zamboni]

my advice for koi is deeper is better.  I have given up on koi surviving in mine, approx. 18' diameter, with a depth of approx. 20" in most of it with a small area approx. 36" deep.  comets and shubinkins have survived previous winters, but not koi.  this winter only a handful of the comets survived, although surprisingly many frogs survived.  it froze over in mid November and didn't completely thaw until early April, and I run a submerged power head pointing up to the surface to keep a small area open.  brother in law with a pond twice the size of mine  didn't lose any of his 20"+ koi, but he has a deep end of almost 5'.  my walls are pretty much vertical for 12", then a shelf around the entire diameter, and I've never had any trouble with the ice.  too much slope would make it difficult to get in and out in the summer. . . . liners get real slippery.   if I were to dig mine all over, it would be at least 42" deep in 1/3 of the area -- which is about as deep as I could go to still reach the bottom without my face underwater.

[whiteram98]

I have 2 ponds running 35000 gallons, they connect and are lined with rubber pond membrane. 1 pond is 3feet deep and connects to the larger pond which is 6ft deep. The ponds are 12x28ft and 6x18 feet. I always run air year round. I have about 20-25 koi any where from 10 to 20". I have lost 2 from this hard winter but you have to expect some loss because it will happen! Deeper is better(LOL) You should always have flow or air to prevent freezing in winter and fish sufficating for lack of oxygen!
Plant all year round also give oxygen even when dormant in winter.  My ledge's arounf the pond are tapered so if kids fall in they could get out. They are 1 ft down then 1 ft in before they drop all the way to the ground. I can send you pics of the pond dig's when your ready to start. I have built ponds for a few years now and have about 10yrs doing it.

[Steve]

Excellent thanks for the info whiteram. When we get ready to start it this spring I may Pm you with a question or two if that's alright. Gonna have to go over there soon and see where they plan to place it and exactly how big it is going to be before we start breaking ground.

[lohachata]

the depth requirement is relative to location when it comes to ponds..the warmer the shallower...but we already know that..and we know that it gets pretty damned cold here in the north..lol
but your city can tell you what you need to know....if i remember correctly they will give you the "Frost Line" for your area...
i think you have to ask the building dept..frost line is the deepest the ground has ever frozen..here in Cleveland it is 36".
it is different for water but not much...
and i agree that deeper is better..i would say that 4' is good..and using a pond aerator or even a pond warmer can be a great asset.....

[whiteram98]

I went 5ft because by me the frost line is 4ft, I wanted to be deeper and also considering you will build up debris, leaves ,mud etc...Feel free to pm me and I can send you some pics or maybe even help if your not to far!

Hope you know what your getting into!!!!!!!!!!!

[Steve]

wow that is great looking

[lohachata]

now that is a gorgeous pond....

[Steve]

What sort of liner did you use on that pond whiteram?

[Saulosi77]

Wow,  great looking pond!

[Bremmon]

I went broke just looking at your pictures... My wife and I were talking about doing a koi pond, but I'm thinking we may have to wait a year... Love what you did with your pond though.