I am currently digging a pond, a koi pond in Northern Ill.
My hole is currently 12ft by 7ft by 3.5 deep. The hole is situated on the south side of my house, just off my back deck.
I have read many different recommendations for the depth of koi ponds, but to no avail it seems there is no solid advice for pond depth that I can find. Is 3.5ft deep enough or does it need to be 5 ft, or do I need 14” below 4ft?? I want to be able to leave my fish in the pond in the winter with some assistance from me.
What depth should I dig my pond to?
Thank you very much in advance.
keepers will tell you that deeper is better, many
recommending 12 to 14 feet for really big fish.
and gallonage buys you the opportunity for your fish to grow
and your water temps and stability will be better.
downside is that you will need high-end pumps and bottom
drains at that depth and good pumps and bottom drains at any
depth more than 3 feet. Regular maintenance requires access
to the bottom. 10 to 14 foot depth requires skill with SCUBA
A nice compromise is 5.5 to 7 feet. You still need the
bottom drain, but can service it with swim fins and a
Thanks for the time to respond to me.
I am learning
that a koi community exists and is much larger than I ever
expected. As such I am learning you can have a varied
degree of involvement in the community and with the pond
Although I am a certified scuba diver, I
think I will pass on the very deep and large ponds unless I
win the lotto. After talking with 2 people down the
road who have smaller backyard ponds that I do, I will dig
to 4 feet and leave it. One guy has a 2.5 foot pond
and he keeps it unfrozen. Not saying his fish are the
happiest in the world, but they look and act healthy this
I will be more involved than this guy with my
pond, but will not be as involved as most of your members
I wish I had the time, money and space to thoroughly enjoy
the pond the way I want, but at this time in my life my kids
demand more time and money than I all ready have.
Thanks again for the time and good luck with all,
Go to 5 to 5.5 feet George. Honest, you will never regret
Think about building up above grade with architectural
stone about 18 to 20 inches. It buys an extra 1000 gallons
in the same footprint, brings the fish up to you so the
interaction is better, and prevents runoff from your yard
from poisoning your fish and filter.
About a foot of
compacted dirt between the stone and the liner gives you the
stability you'll need.
I did some 'engineering' with my neighbor and it looks as
if maybe it can be done and maybe I will raise it.
I'll use granite boulders instead of formed stones, I have
access to a few farms in the area.
Will I be able to see my fish at 5 feet deep??
I'm thinking of running a probead filter with a 2
speed artesian pump with two 3 inch bottom drains, a uv
clarifier and 2 induction jets.
Pond is under a tree, directly under a tree, lol.
The key to seeing your fish is a bare liner bottom, bottom drains hooked to an independent pump,(your skimmer should be run from its own pump to its own filter) and the best biofiltration you can engineer.
The main impediments to gin-clear water are floating (pea-soup) algae and dissolved organics.
You control the algae by using a good UV system inline after your biofilters and denying it nutrients by removing the ammonia your fish generate with excellent bioconversion.
Dissolved organics are reduced with water changes and eliminated with protein extractors.