7 Simple Tips for a Great Koi Pond

My favorite part of my day is enjoying my morning coffee beside the koi pond.  My second favorite is enjoying my evening adult beverage beside the koi pond.  Those stress-free times were few and far between when I started in this hobby.

In the 15 years since we built our first pond, the lessons we have learned could have filled a dozen koi ponds.  Below are  7 simple tips you can leverage to build your koi pond in a manner that will save you money, time and headaches.

Pond Design Tips

TIP 1:  Dig Deep (but you needn't go crazy).  5 feet deep is a darn good depth for koi.  3 feet is sufficient for a water garden and/or goldfish pond.  If you peruse the koi hobby forums you will find hardcore koi keepers advocating strongly for 6-8 feet.  Even living in hot & humid southeast Texas, the benefits of this are minimal.   5 feet is deep enough to keep your koi relatively cool and away from the predators, while shallow enough for most of us to stand with our noggin above water when we inevitably fall in. 

Koi Pond 5.5' Depth at Bottom Drain.  2.5' Depth for Shallow Area.
5.5' Depth at Bottom Drain. 2.5' Depth for Shallow Area.

TIP 2: EPDM Liner is Just Fine -   Having gotten in and out of the hobby a few times, we are advocates for liner ponds.  Like many in this hobby, things can change, like having kids, selling your home or losing interest.  We recommend .45 mil EPDM liner.  When you are a Koi Master, have moved to your retirement home, and have nothing to lose but the kid's trust fund... upgrade to concrete or gunnite.  We evaluated this to the extreme.  The liner was easier, substantially cheaper and in no way affected the health of the fish or our enjoyment of the koi pond.

TIP 3: Raised Pond Edge - ABSOLUTELY!  One of the best choices we made.  Our yard drains toward the pond, our area is prone to heavy rainfall and flooding and we have pets (blind dog, 3-legged cat & more) and children.  With our first pond we wanted the "natural look".  BIG MISTAKE!  We frequently had kids and animals falling in.  The run-off was so bad we stopped fertilizing the yard and using insecticides in the surrounding garden.  In addition, problems with invasive pond plants getting into the beds remains a problem even years after.

Koi Pond: Raised Edge ExampleRaised Edge Example

In this example, prior to placing the liner, the edge was capped with 16x8 concrete block.  Liner was placed over the block, and then trimmed with stone.

TIP 4: Use of Tangential Pond Returns is Optional - Tangential Pond Returns or TPR's are used in koi ponds to facilitate water circulation to create a "toilet bowl effect" in conjunction with your bottom drains.  The Koi Intelligentsia swear by them.  I installed 5, placed 18" above bottom, along the outer wall, and collectively pushed 4,000 - 6,500 GPH through them via a an external pump.

Overtime, to concentrate the throughput, I directed the flow primarily through 2 or 3 TPRs.  Adding another pump was not an option.  Upon review, if I did it over, I may skip this step if money is tight.  Perhaps in a pinch in low flow areas pop in an inexpensive submersible pump just for the water movement.

TIP 5: Shade, Shade & More Shade - In the bright sun of the Republic of Texas, keeping the water clear and algae free is daunting challenge.  In a standard water garden, your in pond plants would do the work of consuming nitrates and keeping the daily algae bloom minimized.  Not so easy in a koi dominated pond.  As you will find out, keeping koi and plants together is akin to having a bull in a china shop.  They are big, messy, and determined to consume every bit of vegetation.  I'm stubborn and creative, so I do manage to maintain a few water lilies and other marginals for pondly aesthetics.  I'll get into UV  Sterilizers in a bit, but first, lets talk about Shade Sail.  Inexpensive, easy to install and not much effort or space is needed to store in the winter, this is a real boon to fans of actually seeing your koi during the summer months.  As an added bonus, it puts shade over my head during happy hour.

TIP 6: Chlorine/Chloramine Remover - RIP to my 4 pet store tester Koi.  Yup!  Learned the hard way that our wonderful water district treats our water with Chloramine.  Chloramine is so toxic to Koi, that my 4 young pioneers were dead within 5 hours.  From the post-mortem, manic internet research frenzy that ensued, I learned of the merits of a wonderful gift of chemistry known as Stress Coat.  I purchase it in gallon jugs and dose it liberally.  Like magic... it almost instantly neutralizes this devil.  I've done 75% water changes several times without a worry using this in conjunction.

Koi Pond FishTIP 7: Aeration is NOT Optional - 
Every great General has regretful losses.  In my case, it was 2 of my prized, imported from Japan, adult koi.  I won't dare mention the cost here.  One fateful summer morning, I awoke to the urgent... distressed sounds of my wife, as she shouted to the kids to get dad.  Tell him every fish in the pond (I have lots) is at the top, and gasping desperately.  More panic ensued as I puzzled out the net of the situation, summarily kicking myself for not replacing a broken air pump, and even worse... I was operating at 50% filtration.  This wasn't the full measure of my neglect, but it was the moment of catharsis I needed to move on to pond 4.0.   Step 1 was a panicked run to my local pond shop to pay an egregious premium for a temporary air supply.  Later, I purchased an aerator like the Atlantic WG Typhoon  which does a great job blasting air to my bottom drains with air diffuser.  I keep a spare also.


What I learned the very hard way is all that wonderful algae that creates oxygen during the day, consumes it throughout the night, meaning oxygen levels can get dangerously, even fatally low, in the wee morning hours.  Your weakest fish, and in my case your largest fish, are most vulnerable.  This was a horrible thing to witness and be responsible for.

Stay tuned for more tales from the pit...

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