Chapter 2 

Sounds like you are ready to dig in!  In most locations, pond depths of 24 inches are accepted as landscaping and do not require fencing, but be sure to check local codes.  24 inches is adequate for protection from most predators, and for over-wintering of any future fish.

Excavation challenges may come up, and if they do, adjustments can be made to the pond contour or pond location.  If shallow water would be the result of any immovable "surprise" it is not the end of the pond.  Even 2' of water will grow some aquatics.  To gain pond volume and provide a deeper portion for over-wintering fish, just relocate these areas.  Here is a friendly tip- be prepared to experiment because of unforeseen problems with nature.  If needed, abandon one solution, and move on to another until the problem is at least temporarily solved!

The next consideration would be the liner to be used as the base of your pond.  The 45 Mil Fish-Safe EPDM Liner material is the most versatile and durable product which works well with the filtration products. Roof liner material should be avoided because of the chemicals used to make it fire retardant. These chemicals can make your fish sick. If you are intent on using roof liner material, make sure it is washed very well.  The best option of all is to use pond liner material made specifically for ponds.  The liner is the primary and often the only water containment for the pond. Considering the total design life and installed const of the pond, using a cheaper liner is a false economy.

An underlayment is not totally mandatory before install of liner, however, if desired, old carpeting can be used.  It must be certain that the material is not a kind that will rot.  The material could be nylon or other man-made material, check label on carpet. Also, take out all metal tags, nails, and staples because these could puncture the pond liner.

One of the most challenging parts of pond construction is consideration for the edge treatment. It is quite common to find edges that look unnatural and even awkward.

The shallow shelf around the pond edge provides a base for a variety of rock shapes and sizes. To create a more natural and interesting edge, use a variety of rock sizes. Interspersing planting pockets for marginal plants or areas where soil and terrestrial plants can be placed along the water’s edge will create an interesting and natural looking edge.  Consider alternating methods of installing the liner and treating the edges so the finished installation has a variety of views.

Always leave about 12" of extra liner above the water line.  Extra liner allows for possible settling of the pond and can be easily hidden by folding behind the edge rocks.

Before adding the water, there should be a clear understanding of how to provide proper filtration for the pond.  Filtration and the associated water movement is what provide both clear water and pleasing sounds.  Filtration is essential to reduce pond maintenance.  The skimmer serves as the foundation for the pond.  It houses the pump and performs a mechanical filtration function by removing leaves and floating debris before they can sink to the bottom.  This greatly simplifies maintenance for all pond components and minimizes the load biological filter.

Therefore, the skimmer is a pre filter and "dynamic settling-chamber," aggressively removing both, coarse debris via the net and fine debris via the filter mats.

The biological filter is essential to "polish" the pond water, supporting huge colonies of bacteria for the nitrification cycle.  Ammonia from the fish waste and decaying leaves is converted to first nitrites and then nitrates in this filter. 

The skimmer also simplifies installation by acting as a plumbing junction box for the pump, pipe discharge and automatic water fill. Similarly, the biological filter/waterfall is an excellent means to create a stable waterfall foundation and pump discharge junction box. Connecting the two filters at the job site is simple, time-saving and reliable. 

The skimmer height is determined once the water level is defined.  Select the water level to match the pond setting, which is usually set below existing grades or adjacent patios/decks The opening in the top of the skimmer should always be approximately one-inch above the water level so debris can skim into the vault.  This can be accomplished by setting the skimmer vault into a specified hold depth below the water level. For best performance, the skimmer should be placed nearly opposite the stream entrance or biological filter. 

Please be aware, you do not need to use a UV (ultraviolet) light or chemicals to make your water clear. These will very essence (bacteria) that is needed to establish clear water. It would be very helpful to research for your self how the nitrogen cycle and bacteria works. All the information is located in libraries and the internet-and is free advice. It is upsetting that so called pond experts at pond supply stores really are experts in selling a lot of things not needed. 

Rocks and Gravel in the pond support aquatic plantings, further enhancing their performance as biological filters, and add beauty and a natural look to the garden pond.  The landscaping around the pond can then be extended directly into the pond because the gravel planting bed eliminates the need for pots, especially for bog plantings along the pond's edge. 

This is the way to calculate "rock formula" for your pond. Calculate the approximate pond and stream area by multiplying the length and width of the pond and then the stream. Then divide the total area by 65 to give the total number of tons of "cobble" to cover the pond drops and edges in variable sized boulders.  Then add 40% more river gravel sized from 1/4 to 2' diameter, so it doesn't look like a gravel pit, and still adds lots of surface area. 

By the way, you may have someone tell you that you should never put rocks and gravel in your pond because it will create deadly bacteria that will kill your fish. Actually, bacteria named Philodian, which comes from nature, removes harmful bacteria in the pond. So nature has been handling this beautifully for centuries. 

It's the amount of rocks and gravel put into a pond, which would be just enough to cover your liner. There are ponds out there with no rocks and gravel and they have dead zones. By using a skimmer system, 80 to 85% of the surface material will be collected and the remaining 10-15% will then fall to the bottom and be broken down by the bacteria, plants, fish, etc. The nitrogen cycle keeps the build up of sludge from occurring.  The bottom acts as a natural biological filter.  Therefore one or two inches of rock and gravel will be enough because the oxygen in the water can come down to the bacteria, which needs oxygen to be able to break down the nutrients. 

To sum up the theory of rocks and gravel, here are four reasons for using them:

1.  It makes the pond look very natural

2.  It helps keep the liner down in case of any pressure situation.

3.  It protects the liner from the sun.

4   Seeding the pond with bacteria besides the biological filter box is recommended.

The fish waste and any other matter will settle to the bottom and nitrogen cycle works on it.  There will be no build up of sludge.  You will still be able to see the rocks, even after the pond is 14yrs old, as there is hardly any build up at all.)