By Kent Wallace, Livingwatersolutions.com
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Predators, such as herons, are often a problem in backyard ponds. There are many options available when dealing with animals that may view your prized fish as prey. |
Living with a pond or water feature means dealing with a variety of issues as the pond matures. Many of these issues can be dealt with at the maintenance level, but some of them need to be addressed as construction issues.
String algae. Many types of algae exist and controlling them can be frustrating. There are many good sources of information available on the complicated nature of algae growth, but a proper understanding of your system will go a long ways in dealing with the various types of algae you will encounter.
The carpet of algae that grows on the sides and all the surfaces of your pond is a natural and healthy occurrence. This algal surface houses many complicated biological processes and should exist as a very short film much like the appearance of an indoor or outdoor carpet. When your pond isn’t maintained properly or substances are introduced into your pond that promote algae growth, it can get out of hand. String algae or blanket weed is a nuisance and can be unsightly. It grows like long, flowing hair and like all plants, algae has nutritional requirements needed to flourish. Some of these requirements are nitrates, minerals, sunlight, low dissolved oxygen levels, poor circulation and varying ranges of temperature. Some types of algae like warm water conditions and some like colder water. Algae can even consume ammonia produced by fish and decomposing material in your pond.
Building the best pond you can afford is always the first course of action. Good circulation, filtration and oxygen are a good start. A poorly conceived system is a good place for algae to flourish. Even well-built systems can suffer algae problems. One common source of nutrients for algae is decomposing material on the pond bottom. Keep your pond as free of debris as possible and do regular partial water changes. Keep your filtration system clean and healthy at all times.
If you have fish, feed them a good quality food without a lot of fillers that just turn into waste solids your filtration system has to deal with.
When battling string algae use products that are harmless to fish. There are many treatments available so choose wisely. Only use treatments as a last resort and don’t become dependent on their regular use without addressing the pond’s mechanical issues.
When designing a pond, depth is a good thing. Sunlight affects the upper 18 to 24 inches of pond depth. This is the region most prone to single-celled algae growth. If your pond is shallow, the entire volume of water is affected by the sun. Building a deeper pond gives you a cushion of water volume available that is protected from sunlight.
Single-celled floating algae. This is the type of algae that turns your water pea soup green. This can be dealt with by using massive filtration, but in modern systems an ultraviolet light is commonly installed in the piping to eliminate this type of algae. A UV light doesn’t kill algae directly but disrupts its cell walls and prevents reproduction. The dying algae can then be taken out of the pond by the filtration system.
Choose a UV light according to the flow rate of the water circuit you intend on pumping through it. Do not choose a UV light based on pond size. The algae must be bathed in the UV light for a long enough period of time to have an effect. Pumping water through the light housing too fast makes it ineffective. As an example, if you intend on placing the light in a circuit with 1,500 gallon per hour of pump flow, choose a light rated above that flow rate.
New to the market are sonic devices that pulse a series of different sound wave frequencies through the water several times a second with a pause. These units have shown promise and are a good choice for large projects where UV lights get very large and expensive.
Predators. These come in many shapes and sizes and are another problem to be dealt with. Predators are a regionally specific, but the most common are herons. They have long legs and a lot of patience. They can stand in a shallow pond and kill and eat all of your fish in a short time. The best huron defense is a deep pond. Depth gives the fish an area in the pond to go to where the herons can’t reach them. There are also motion-sensor devices that fire a water jet that sweeps the area. This is a good method for four-legged predators as well. Tying thin wires across the pond can also help deter birds. You can always consider a good dog, too!
Water leaks. Mechanical leaks in plumbing and filters are fairly easy to repair, but leaks under the water surface and through the pond liner are much harder to deal with. Use a good quality liner during construction and use polyurethane sealants instead of silicone or other sealants for all penetrations around skimmers, bottom drains and current jets.
The biggest source of water leaks in liner ponds are areas around the perimeter where the liner gets pushed down below the water line. These areas are usually hidden under loose edge material and difficult to find. This is a good case for a better method of construction that incorporates a secure edge for the liner. This could be concrete and decorative rocks, foam or other edging material that will stay in place over time.
If your project is large in both size and expense or situated in an area that would make a water leak a serious problem, polyurea is a much better choice for liner. Polyurea is a spray applied plastic coating that is not a “do-it-yourself” product, but it is fast becoming known as the best on the market. If you are considering a commercial application or wish to build a fairly permanent structure, polyurea is the only way to go. The higher initial costs are outweighed by the long-term savings of never having to replace it. Replacing a liner once or twice in the lifetime of a pond makes polyurea easily affordable, not to mention its amazing elasticity and ability to resist puncture.
Most pond issues are better dealt with during the design-and-construction phase rather than during the ownership-and-maintenance phase. Decide what you want long term and think of your project as an investment along with a gift to yourself.