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, natures 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 dont use bottom drains, they cant 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 isnt 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 ponds bottom. Most liner ponds Ive 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.