Koi Pond: Liners Vs. Professional Construction

Why is there so much talk about pond liners? Which ones are UV protected, or stronger, or last longer? I am by no means an expert on liner technology, nor have I ever used them in my 26 years of designing and building waterfalls. If you’re a “liner guy” disciple, I’m sure you’re thinking, “Oh no, here he goes.” To tell the truth, I have been minding by own business for over two decades, just watching, reading and listening to all the “experts.”

I’ve listened to how “pond liners are simple to install,” and “pond liners are inexpensive compared to concrete and steel,” and “pond liners are quick to install.” Or “pond liners last for 50 years,” “pond liners bring higher profits to pond construction and waterfall construction,” and “liners don’t contaminate the water with alkali as does concrete construction.” Yes, I’ve almost sold myself on listening to the facts of the “experts.” Well, not quite, due to a few facts of my own.



So, a pond liner is guaranteed for 40 to 50 years? I would have to agree with that, as long as you leave it in its box the whole time. Too bad a liner manufacturer’s warranty doesn’t include damage from gophers, ground squirrels, chipmunks, rats or mice. Or tree, plant and weed roots. Or from stretching and punctures in the liner due to heavy rocks and other sharp objects. Startling fact: a puncture only the size of a pin hole can cause a pond to lose one drip per second, or 5 gallons in just 24 hours. That’s a pin hole, not a hole made by a pair of buck teeth on a burrowing mammal.



Imagine along with me for a minute. You have spent $350 on a pond design and then $8,000 of your hard-earned money for a pond and waterfall. This water feature is impressive. They dug a big hole, piled up some dirt at one end, draped a large rubber liner over the whole thing, and placed giant boulders all around the fish pond and on the dirt mound. Smaller rocks fill in between the boulder and additional rocks cover the liner in the pond. Now, it’s two years later and you’ve just come home from a two-week vacation to find the pond half empty (or half full, if you’re a positive person).

There must be a leak! How did this happen? Where is it? No problem, you think, I remember the salesman’s pitch: “If you should ever get a leak, just clean off the area around the hole, dry it off, and using the directions enclosed in the patching kit, apply this patching material.” But there’s only one problem: Where is the leak? or leaks? How do I find them? And if I do find them, and I’m successful in patching them up, what’s to keep it from leaking again?



Okay, I’m going to snap my fingers and you’ll wake up. “Snap!” Surprise! That was only a mental exercise with a happy ending. It wasn’t real! Or was it? Yes, it was. The short story you just heard was true. One out of every eight projects we do involves replacing the leaky liner for an angry fish pond/leaky liner owner.



Why am I finally speaking up now, after 26 years and well over 1,900 waterfalls and fish ponds? Because I’m angry, too! Not at the “liner guy” who sells the pond liners, but at his disciples around the country who are bragging how much money they make in just one or two days. I’m not upset at the fact that they make in two days what takes me six to seven days to make in constructing my fish ponds of rebar and 3000 psi concrete.

My ire stems from having to charge $8,000 to replace a $6,000 liner pond that lasted only two years. (A pond liner with padding didn’t stop a tree root which traveled 25 feet to do its destructive work.) For only an additional 16% in cost, that client could still be enjoying his original pond, stress-free, for his lifetime and that of his children and grandchildren and great-grandchildren.



The main features touted by pond liner promoters are simplicity, low cost, quick installation, and extremely high profits. In an article published in his catalog/magazine of liners and accessories, the “liner messiah” has obviously taught his disciples well, as you can read in this excerpt:

“If you hire us to install your pond, you get a choice of buying it with or without a stream. We offer no other choices! The pond we build covers an area of 11 by 16 feet, has a maximum depth of 2 feet, and a beautiful waterfall. We’ll build your pond in one day. The basic pond costs $5,100 and if you want to connect the falls with a stream, you’re looking at an extra $1,000. That’s it. End of story. No mas.”

That’s what Ernie Selles, president of Patio Ponds and disciple of the “liner guy,” said. Another quote from Ernie in the same catalog is, “I get out of bed every morning and look forward to going to work in a way that I never had before.” I noticed he didn’t mention how well he slept.



Let’s do the math on Ernie’s installation. The pond, stream, and waterfall cost is $6,100. The actual retail cost of the kit is only $1,000. $5,100 profit for only one day of labor. Notice: unlike our package, they offer no lights, no autofill, and the pond is only two feet deep. Yet three feet minimum are required for koi fish. A two foot pond affords no protection from predators such as raccoons and herons, and the shallow depth is affected easily by rapid temperature changes, causing undue stress on the pond’s inhabitants. They do not like to construct ponds over two feet deep, because they are more susceptible to cave-ins.



We would build the same pond with a depth ranging from 3 to 3 ½ feet, with no shallows for dining predators. It is constructed of rebar 18 inches on center with a shell of 3000 psi concrete (sidewalks and driveways are typically 2000 psi). This 7 sack, 60% pea with fiber mix is so dense that it’s waterproof. However, we still coat it with ThoroSeal. The pond is equipped with two anti-vortex bottom suction drains, a skimmer to remove surface debris, and an out-of-pond pump that produces 5000 gallons per hour at only 2.6 amps, compared to the liner guy’s pumps which are only 4200 gallons per hour at 7.6 amps – over twice the cost of energy! In addition, you have to pull his heavy cast iron monster pump out of the water to clean out debris.



We would also include a state of the art Aqua Ultraviolet filter and UV light – the best money can buy. The liner guy’s filter needs to be disassembled in order to clean it by hand. The Ultima II filter requires the simple turn of a handle to back flush the debris. This system has been operational in my water features for six years with no problems. We include an ultraviolet light in our system that kills the bacteria that create smells, kills pathogens that cause disease and algae spores that turn the water green. This light has a wiper arm that cleans the internal lens without the need to open the light.



We also offer an automatic electronic water level control system, the “AquaFill” by Aquamedia Corp.com that keeps the water level of the pond constant. Pond liner installers use floats that are mechanical like the float in a toilet tank. Mechanical fillers can corrode and stick, causing overflows and even poisoning the fish with excess chlorinated water. However, the AquaFill does not stick or corrode.



Not only are all our ponds designed a minimum of three feet deep, we build caves for the turtles and fish to hide in. With pond liner construction, rocks cannot be cemented to the liner and consequently many are loose, creating a hazard if someone were to step on them. Kids will be kids and I promise they will eventually be running up and down the falls. We have no loose rock because they are all cemented in place with Aquamedia Mortar Mix, which is not only three times stronger than regular mortar, it is very dense. As a result, alkali will not leach out into the water and create a pH problem. Regular mortar mix is porous and water passes through the joints of the rock, carrying with it cement residue. This in turn creates stain trails high in pH, easily poisoning the fish.



In conclusion, as an educated customer, would you pay $6,100 for a rubber pond liner or spend the same amount or a little more to get a shell made of concrete and steel that not only would never leak, but would last for decades. So what are we as contractors looking for? Exorbitant profits or peace of mind with long-term, happy clients?



It is more enjoyable for me to get a call eight years down the road from a content client than to get a complaint of a leaky pond. What does the “liner guy” disciple say? “Sorry, we only have a one year warranty”? Or do they go back and remove all the rocks, pull out the pond liner, clean it, repair the leaks, and replace all the rocks and equipment at no cost? Liners or professional installations?

You say pond liners are professionally installed.

Then why is the very same liner kit sold to homeowners and do-it-yourselfers? The reason is, it doesn’t take an experienced professional to install one.

All you need is “a garden hose and a shovel”!

Look before you leap, and ponder before you weep. Happy koi, peace and joy.