pond construction fundamentals

Clarke Koi Ponds inc. relies on educated approach to pond construction. With decades of study and experience to guide us, we can explain to you why you need a bottom drain while many suggest you do not. Why you need to invest in balanced approach to pond design instead of the next hyped piece of equipment new to the pond scene

Being able to substantiate advice with science and logic is what really matters. This ability is what sets Clarke Koi Ponds apart from the competition
  • The classic my brother and his friend built it
  • The site is cleared, collar and membrance installed
  • Stone work begins after filling and taping
  • All the ponds needs now is some soft scaping

The Most Common Pond Building Mistakes

  • Building the pond too small and/or too shallow
  • Not allowing space for and/or not installing a properly sized and capable filter
  • Not installing a bottom drain
  • Impulse buying, poor planning and rushing the job
  • Over estimating your abilities and not enlisted the help of those with experience building ponds
  • Trying to build a good pond with little or no money invested
  • Buying expensive koi when neither you nor your pond are ready
  • Under estimating the amount of time and money required to build a proper pond
  • Not using the proper pond building techniques [no concrete collar, no bottom drain etc]
  • Hiring someone who has a novice level of knowledge [ie. nurseries, landscapers and yes, even most pond "experts"- see paradox ponds]

The collar is integral, and every year we rebuild ponds to incorporate one

Concrete Collar

A ring of rebar reinforced concrete sets the level for the pond. It also defines the site during excavation, stops side wall crumbling and provides a stable and level base for the stone work

Pads and footings should also be poured for waterfalls and larger stone - these should be tied into the collar

Read more about Concrete Collars
2 Bottom drains went into this 8 foot deep pond


Regardless of climate, a pond should have a deep section of at least 5 feet, preferably 7'. Fish kept in shallow ponds experience a baseline level of stress

Creating the proper sloped pond shell to channel debris to the bottom drain is key

Read more about excavation
Bottom drains vacuum the bottom of your pond and can remove large debris

Bottom Drain

With a properly dug shell, the bottom drain will remove all debris from the ponds bottom out to the external filter

The bottom drain is essentially a 24/7 vacuum, constantly removing detritus from your pond. Never have to drain your pond again for cleaning

Read more about Bottom Drains
External filters are easier to maintain and provide better water quality

external filtration

Properly sized external filters [minimum 10% of ponds volume] should be easy to clean and provide good water quality for your fish

Any filter that will fit in the back seat of your car has been designed for just that, not to filter a pond effectively. Undersized filters translate into a lot of maintenance

Read more about Filters
The liner looks pretty untidy initially. 2 people are required to get it in properly

underlayment + Liners

A heavy duty 45 mil E.P.D.M. liner is a solid choice for longevity - PVC should be avoided

Protecting the liner with the proper geosynthetic underlayment is imperative. Carpeting, newspaper and sand provide some protection but are flawed choices

Read more about Liners
Taping folds takes a bit of time but is well worth the effort

Liner Fold Taping

After being carefully placed in the pond shell, the liner is folded to keep wrinkles to a minimum

Folds are then taped down with liner tape for both aesthetics purposes and to help eliminate dead spots. Wrinkled liner can also accumulate debris

Read more about Liner Taping
Pond skimmers can pull in floating plants too


Skimmers remove surface scum and leaves. They are a great addition as they allow for high flow rates and are therefore great at supplying bead filters with a large volume of water

Read more about Skimmers
Read a review on Savio skimmers
Ponds require a lot of oxygen, particularly in the heat of Summer


Both filtration and aeration are keys to success in any fish pond. I have yet to see a pond that is not overstocked and nitrification relies heavily on sufficient oxygen content

Try to maintain 80%+ saturation at all times

Read more on Aeration
Jets are great for exercising fish and moving debris to the bottom drain

Pond Jets

Jets provide water quality enhancing re-circulation which also exercises the fish developing their musculature. Koi get bored and need stimulus - jets provide this

We have success using about 1,000 g.p.h. for each jet and you want to have at least 2 jets in place
2 Dolphing pumps set up with jet valve control

Water Pumps

Hi-efficiency, non-submersible pumps are utilized most of the time. They consume less hydro and last longer than submersible pumps.

Although more expensive initially but provide much better value over time

How to Install a Pump
Getting all the connecdtions right takes some time


Understanding how the whole system will optimally function in the most efficient manner is paramount

A quick example... I have seen many jobs were water is being pumped in excess of 30 feet [to the head of a stream for example] instead of being gravity fed to a drum and pumped only a short distance - this is poor design
clear water, healthy fish - the ultimate goal

finishing Touches

The all important aesthetics means that no liner, wires, piping or anything manmade is visible

The finishing details require a lot of time

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more questions ? Toll Free Consulting available
Remember, if you do have any further questions, we do offer a consulting service by phone for $95/ hr. 1 hr. minimum charge. We have a huge archive of photographs and video we can email, and our fee includes follow up assistance

Visit our our video blog section for actual pond construction videos of some of our projects