Aquatic Construction: Pond FAQs

Pond FAQs - Materials

Answers to common questions related to Ponds

Kenney answers FAQs about Ponds and Water Gardens

Design · Materials · Fish · Plants · Algae Control

Materials

<> What is "Fish-Safe" liner?

There are many types of liners on the market that could be used to build a pond, but very few of them are stamped "Fish-Safe". A "Fish-Safe" liner, unlike all other liners, is tested and guaranteed free of all properties that could kill aquatic life. It is easy to determine whether a liner is "Fish-Safe". Look for the stamp imprinted on the liner.

<> What is the difference between EPDM, Butyl Rubber, PVC, Polyethylene, and Polyolefin?

EPDM-Ethylene Propylene Diene Monomer
This material is Aquascape's liner of choice for ponds requiring liners less than 45 ft x 100 ft. It is very easy to work with, flexible at cold temperatures, and cost effective. This is a common roofing material and needs to be stamped "fish-safe". It has a 20-year life expectancy and offers optimum UV resistance. Once buried under rock, no deterioration is anticipated. It's extremely puncture resistant and non-toxic to fish or plants.
Butyl Rubber
This material is excellent for ponds, but is more expensive than EPDM. It has a 20-year life expectancy, but cracks or flakes if exposed to sunlight.
PVC-Polyvinyl Chloride
This material is a thermoplastic membrane with a 7 to 15-year life expectancy.
Polyethylene
This material is Aquascape's liner of choice for ponds requiring liners greater than 45 ft x 100 ft. It is an Olefin-based membrane, a stiff product best used on ponds 45 feet and over. It's light weight which makes it ideal for larger applications. It is factory seamed to the specific size of the pond (in 5 foot increments) and is highly puncture resistant.
Polyolefin
This material is stiffer than EPDM. It has a 5-year life expectancy.

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<> How much does the EPDM and Polyethylene weigh?

A 45 mil EPDM liners weigh .292 pounds per square foot.
A 30 mil Polyethylene liners weigh .15 pounds per square foot.

<> Why should I use underlayment instead of other materials?

Underlayment is easy to apply and contours to all shapes, both horizontal and vertical. It "breathes" so gases can escape and provides excellent protective padding for liner. Newspapers are labor-intensive to apply. They are inexpensive, need to have a 1/2 inch thickness, and are not very professional.

Old carpet is inexpensive but does not contour well to curves of pond and is not very professional. Sand will not stay on the sides of shelves. It is sometimes used below underlayment in rocky terrain. In these cases, use the finest (non-coarse) sand.

<> Why don't I need underlayment under my stream liner?

The pressure from the weight of stone and water that is exerted on the stream is not as great as the pressure in a pond. If the stream runs over very rocky soil, underlayment or sand may be put down first.

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<> What is hydrostatic pressure and what measures can be taken to reduce it?

Hydrostatic pressure is when water from a high water table builds enough pressure beneath the liner to cause it to "bubble up". Pressure relief valves are one method of relieving the build-up of hydrostatic pressure beneath the liner. Simply install the relief valves into a bulkhead fitting that has been installed into the liner. The pressure relief valve is a spring-loaded valve that will open when the hydrostatic pressure builds, allowing water to enter the pond. Once the pressure is reduced, the valve will close.

<> Why should I use a skimmer?

Removes and collects leaves from the top of the pond.
Continuously removes floating debris.
Will not drain ponds dry.
Simplifies choosing a pond site, building near trees is no longer a problem.
Hides the filter system outside of the pond and easily disguises the plumbing.
The skimmer filters the pump and prevents the pump from getting clogged.
The skimmer vault is a perfect spot to hide the water fill valve.
The skimmer opening is only a few inches below the pond's surface, so the pump can never pump your pond dry even if there is a leak in your plumbing, stream or waterfall.
The skimmer uses the highest oxygen surface pond water which is essential for maximum productivity of your biofilters.
In cold climates, the skimmer only recirculates the top water, if you feed the skimmer water back onto the pond, by-passing the waterfalls. This reduces heat loss and keeps your pond operating longer.

<> What is the function of the weir flap in the skimmer?

The weir flap causes the pump in the skimmer to draw water off the top 1/8 inch of the surface of the pond. This will maximize the amount of debris that will be drawn into the skimmer.

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<> Where is the ideal water height on the face of the skimmer?

Approximately 3/4 inch down from the opening of the skimmer.

<> Will fish get caught in the skimmer?

Yes, if they are small, usually under about 4 inches long. We recommend leaving the skimmer lid off for 1 to 2 weeks after introducing fish to the pond and simply putting any fish caught in the skimmer back into the pond. After about one week, the smaller fish will learn not to swim close to the skimmer opening. The larger fish will actually swim in and out of the filter looking for food and apparently enjoying the current (like a fish treadmill).

<> What are the two holes in the back of the skimmer?

The large and small hole on the right (if facing the back of the skimmer) is for pump discharge and the electrical cord. The 3 inch hole to the lower left is for the skimmer overflow.

<> Why should I use a BioFalls^®?

Supports large colonies of bacteria and enzymes.
Easy to build natural waterfalls up to 35 inch high; not vulnerable to collapse like a dirt berm.
Keeps water crystal clear without chemicals.
Helps aerate and filter the water of fish waste and organic debris.
Adjustable waterfall widths.
Large capacity.
Built-in rock shelf.
Simplified filter cleaning.

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<> What are the nets that come with the BioFalls^®?

The nets should be filled with a substrate, such as lava rock, for the bacteria to colonize. Fill each bag with approximately 30 to 40 pounds of lava rock.

<> The bulkhead for the BioFalls^® and skimmer has one rubber washer and one plastic washer, what side do they go on?

The rubber washer is inside the vault; the plastic washer is outside.

<> How long should I run my pump?

Pumps should be run 24 hours a day, 7 days a week to keep the ecosystem functioning properly.

What is the difference between high-efficiency and low-efficiency pumps?

<> What is the difference between high-efficiency and low-efficiency pumps?

High-efficiency pumps are higher quality and will last longer and use less electricity. Low-efficiency pumps are less expensive, but use much more electricity.

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<> Can I use an external (non-submersible) pump?

Absolutely. Just plumb the foot valve or pump intake into the skimmer box below the filter media or net.

<> How long is the pump warranted for?

All pumps are warranted for one year.

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<> What do I do, if the pump interferes with the filter mats and PVC support tubes inside the skimmer?

The skimmers are designed to accept a number of different pump models. Certain pumps may simply require cutting a slot in the filter mats and/or removal of a support tube.

<> What kind of oil is in Aquascapes pump?

Nishiki White Oil. It can be replaced with ISO 32 Machine oil or 10 W 30 Non-Detergent Oil. We have not had problems with it leaking.

Pond and Water GardenSpecialist

Pond FAQs - Materials

Design · Materials · Fish · Plants · Algae Control

Materials

Liner

Skimmers

BioFalls®

Pumps

Pond and Water Garden
Specialist

BioFalls^®