Pond Liners: 7 Reasons Why I Don't Use Them

1. Liners will eventually leak. Manufacturers have varying warranties, ranging from 15 to 30 years, with a 75-year life expectancy. In reality, it will definitely last as long as the guarantee claims as long as you leave it in the box, and store it in your garage.

Once you place it in the ground, nature’s forces begin a contest to see which will break its water-tight integrity first. Vying for the title of culprit are gophers, ground squirrels, chipmunks, rats, moles, roots from trees, plants and weeds, sharp rocks, heavy rocks, sharp objects, and moose (if you live in Alaska).

If a leak does develop, it is next to impossible to locate it without removing all the rocks covering the liner, draining the pond, spreading the liner out on the ground, and inspecting every square inch. A tiny pin hole can lose five gallons every 24 hours.

2. Bottom drains cannot be utilized with liners. Liner advocates discount the use of bottom drains primarily because they would rather not, since approximately one half the sources for leaks in liner ponds are from bottom drains. When the liner is cut to install the drain, sealants are used along with pressure rings to make a water-tight seal. The sealants dry out or break down and seal collars warp, resulting in time-consuming, costly repair.

3. You cannot use out-of-pond pumps. Since liner advocates don’t use bottom drains, they can’t use above-ground pumps, which leave no other choice but to use sump pumps. These pumps were originally designed to pump water from sump pits in basements and cellars. They are not designed to save energy; in fact, they are the greatest consumers of energy per horsepower of all pumps. The largest retailer/wholesaler of liners, pumps and accessories sells a sump pump which produces 4200 gallons per hour at 704 watts for $339.00. This pump needs to be pulled from the pond to clean debris from its intake screen. It is a potential shock hazard to fish and humans and is filled with oil, which has the potential of leaking out and covering the surface of the pond.



In contrast, an above-ground pump that supplies 600 gallons more per hour (4,800) for less than half the energy cost (348 watts) and costs over $100 less. Running this pump 24 hours per day will result in a savings of over $500 per year over the sump pump. In other words, the energy savings would pay for the above-ground pump and put an additional $270 cash in your pocket the first year alone.



If that isn’t enough incentive, a second reason to use the above-ground pump is that there is never a need to worry about it clogging since we install two 8" anti-vortex drains on the bottom. The only maintenance required is to occasionally remove the lid from the leaf basket on the pump and dump the debris from the catch basket. Because this is a high-efficiency pump, it is extremely quiet, and standing right next to it you can barely hear it running.



With liner ponds the sump pump is located at the outside edge of the pond, not in the middle as in professional concrete and rebar constructions. We place two 8" anti-vortex drains in the middle of the pond, 24" apart. As fish waste and other suspended particles and algae spores settle to the bottom, they are drawn into the drains and taken out by the filter. An ultraviolet light is placed in series between the filter and pond return in order to kill pathogenic bacteria which can cause disease and turn the pond green.



In deeper ponds that use liners, all the waste material settles and collects on the bottom and rots, creating ammonia that is toxic to fish and other aquatic life. Because a sump pump is located near the outer edge of the pond and not in the middle on the bottom, maximum efficient circulation cannot be reached. This creates toxic cloudy areas in the pond’s bottom. Most liner ponds I’ve seen are only 24" deep, and circulation is not an issue in these cases. However, koi fish are not recommended in these kinds of ponds; koi experts recommend a depth of at least 3 feet.

4. You cannot use a high pressure maintenance free biofilter with a liner pond. When using a sump pump, you have to use a gravity feed bio-falls, down-flow or upflow filter. All of these are inefficient and result in high maintenance costs. They need to be cleaned often by removing all the waste-laden filter media. To say the least, this is a filthy, stinky, messy job which neither my female clients nor most of my male clients expect to perform.

Aqua Ultraviolet’s high pressure filter contains state-of-the-art technology enabling it to simply be back washed with a turn of the handle. The discharge hose can direct the fish waste and particulate debris down the drain, or it can be used to water the garden or lawn. The high pressure filter is designed to handle five to ten times the volume of water that a gravity flow unit or bio-falls can handle.



In addition to all this, the patented bead design of this filter allows for maximum surface area in which nitrifying bacteria can live and break down nitrites. The “Liner Guy” wants you to use his messy, dirty, stinky inefficient filter because it is his filter, and it costs very little to manufacture compared to the professional bead filter. My opinions about filters come from many years of experience, and trying nearly every one that is on the market. I even jumped on the “filter bandwagon” for a couple of years and used my own design.

Why? Because of the unbelievable profit margin! When I discovered the Aqua Ultraviolet filter advertised in several pond magazines, I gave it a try. I’ve been using it for over ten years with no problems whatsoever. My clients clean the filter with the turn of a handle and stay clean themselves. A great side benefit to this filter is that you can have twice the number of fish in your pond than when using the inefficient gravity filters. By the way, this is not a paid endorsement of their product!

5. Safety is a concern when pond liners are used. After a hole is dug, a pond liner is placed in the hole and then it’s filled with water. Rocks are then placed around the perimeter of the pond to cover up the edge of the pond liner, and more rocks are piled up on a mound of dirt covered with another liner to create a waterfall. From my 26 years of experience, I’ve learned that many adults are just like kids when it comes to ponds and waterfalls.

They inevitably climb on the rocks of the waterfall and the pond’s edge. Since the rocks are all loose, they can move, tilt or shift on the pond liner, resulting in someone falling and getting hurt or, worse, drowning. With professional concrete and rebar construction, all the rocks are cemented in place, providing a secure foundation to walk or climb on.

6. Pond liners limit pond shape and configuration. Why are most liner ponds circular or oval in design? Because pond liners are dispensed on rolls and therefore available only in square or rectangular shapes. If an L-shaped pond was designed, you would need to bunch up an inordinate amount of pond liner into the inside corner. Not only is it wasting expensive square feet of pond liner material, it makes it difficult to stack rocks on top of the bunched up liner so as to cover it up.

Oh sure, “Liner Guy” you’re thinking, why doesn’t he mention that special shaped pond liners can be custom made? Okay, I’ll mention it! Custom pond liners can be made to order. And now I’ll mention that this customized pond liner is going to cost you as much as constructing a professional pond with rebar and concrete that will last a lifetime. There, I mentioned it!

7. Last but not least, Integrity. When I read articles written by “the Liner Guy’s” disciples, bragging about the ungodly profits derived from pond liner construction, I can’t help but wonder how they sleep at night. The profit derived from one day’s work -- digging a hole, dropping in a pond liner, covering its surface and perimeter with loose rock, and plugging in an energy-sucking sump pump -- equals what I made in four or five days of labor. One big difference: their warranty is one year, if you’re lucky; but one built with concrete and steel is for a lifetime!



I’m the person that the past customers of “the Liner Guy” called two or three years down the road, asking me to fix the leak in their stinky green liner pond. A client in Poway, California paid $6,500 for a liner pond with a necklace of rock around the perimeter and a 3 x 4 foot fiberglass waterfall at its edge. I actually had to suppress a laugh when I saw it out of respect for my client’s grief.

This pond had a bottom drain that leaked; however, the major loss of water stemmed from a tree root puncture. In addition, it was obvious that this “Liner Guy” disciple did not have his customer’s long term financial well being in mind after I discovered a cheap, 7- amp energy-sucking “Jacuzzi pump. We replaced it with a 3.6 amp high-efficiency pump that supplied nearly twice the flow.



Next, we pulled out the liner, reconfigured the pond’s oval shape to serpentine, and constructed the pond and waterfall shell using rebar (8" on center) and 3500 psi concrete with stealth fiber added. We installed two 8" bottom drains, added a professional skimmer, a Venturi air supply valve, a natural rock waterfall, a turtle island that supported a 25 foot bridge spanning the pond, an “Ultima II” high pressure, back-washable filter, ultraviolet light, lighting in the pond and waterfall. plus an electronic AquaFill pond water leveler. All this took us eight days from start to finish and cost only $2,000 more than the client originally paid.



In Conclusion: Is it any wonder why I despise the “get rich quick” scheme of pond liner construction? The “liner guy” hates hearing me refer to concrete and rebar ponds as “professional construction.” They insist their liner ponds are professional construction. And if so, why do they sell the very same kits to do-it-yourself homeowners as to the construction business people for hire?



I am proud to claim over 1,900 satisfied customers over 26 years. Ninety-five percent of my clientele comes from referrals by satisfied customers. I don’t have to wonder why that is so.



Is there a place for liner ponds? Yes, if you’re renting and expect to move in two or three years. Or if you’re setting up a temporary display. No, I’m not totally against liners. They’re great for truck beds and cheap swimming pools! Actually, I have made thousands of dollars over the years from pond liners – by replacing them with concrete and steel!

An ounce of prevention is worth a [pond] cure. Happy koi, peace and joy.