Is their more to building a pond then digging a hole in the ground and putting a liner in?  Most individuals make the mistake of not properly designing and filtering the pond. The cheapest way to build a pond is to do it right the first time.  Cry once and get it over with.  

First let’s start with the construction; take a look at the surroundings making sure the pond blends in adding to the harmony of the landscape. Ponds may be constructed of liners, fiberglass, or concrete and should be at least 3 ft.  or deeper for Koi. The different types of construction all have their advantages and disadvantages. You need to decide which one fits your needs and budget. No matter what you decide to construct your pond with, the most important item of any successful pond is the filtration system.  

Pond Filtration

With a good filtration system no one should have green water or water quality problems. The problem is most people will dig a hole in the ground, throw in a liner, add some fish, and then decide they need a filter.  The filter needs to be at the top of the list. You need a method by which to remove all the fish waste, dead plant material, and debris blowing into the pond before they decompose. This reduces the level of dissolved pollutants and unhealthy bacteria in the pond keeping the water quality compatible for fish life. When someone calls with a fish problem I always check the water quality first. The most common reason for health problems with fish is poor water quality. If you take care of the water quality the fish will take care of themselves. 

Let’s take a look at the basic requirements for good filtration which are pumps, bottom drains, skimmers, jets, solids removal, biological filtration and U.V. lights.  

First we need to remove the waste from the pond by using bottom drains or submersible pumps on the bottom in the deepest part the pond.  All ponds can benefit from bottom drains to remove the solid waste from the bottom of the pond. Fish and plant waste collecting on the bottom of the pond can lead to water quality problems which leads to green water and sick fish. There are several types of bottom drains depending on your needs. A submersible pump capable of handling solids can work like a bottom drain on smaller ponds.  

Secondly skimmers work great for removing leaves, grass, and dust from the surface of the pond. They also break the surface tension of the water.  There are several types of skimmers on the market from large black boxes to midsize and smaller easy to hide units. Some units will even pull water from below the surface if your water level is to low, to keep your pump running. 

To start the process we a need pump, to either move the water to the filter or move the water from the filter back to the pond at the correct flow rate. Pumps come in two different styles submersible and external. The submersible pumps work well for water features and small ponds less than 1,000 gallons. Once you step over 1,000 gallons I would recommend an energy efficient external pump. Energy efficient external pumps can pay for themselves in electricity savings the first year, self priming models are also available in the larger sizes. If you are using a submersible pump, during the winter, nothing is more fun than wading in your pond, on a 30 degree day, to clean out your clogged up submersible pump which is sitting on the bottom of the pond. This gives a whole new meaning to the phrase "Blue Northern" (or Southerner depending on what part of the country your from). The type of pump and placement can have a large impact on your filtration.  

Should you pump feed or gravity feed you’re your filtration system? Pumping the water to the filtration system will puree the solids, making them more difficult to remove the dissolved pollutants in the water will make the filtration system work harder. The advantage to a pump fed filtration system is they are easier to install.  

Using a gravity fed filtration system is the most efficient way to remove solids from the pond. The gravity fed systems take more time to install but they will greatly reduce the dissolved pollutants, increases water quality and water clarity.  

Let’s take a look at the different steps of filtration.  

During the first phase of filtration you need to remove as much of the solids as possible from the water before it enters the biological filter. You can accomplish this using several methods or combinations. A settling chamber works great and can be enhanced when using gravity feed from the pond. One of the most effective settling chambers is the vortex chambers. To keep this short and simple I will not go into great detail on how the vortex works. Call me, I will be happy to explain in great detail how the vortex settling chamber works. The other method of filtering out solids is by using mechanical filtration to remove the solids. The combination of vortex and mechanical is the best. Your main goal at this point is to have the water as clean of debris as possible prior to the biological filter.  

The second phase may be integrated into the first phase, you need to remove the smaller particles. This can also be accomplished with foam pads, brushes, Springflo or filter mats. 

The third phase of filtration is the bio-filter. The cleaner your water is when entering this stage of the filter, the better it works. The bio-filter can be greatly enhanced by oxygenating the chamber. The biological filter removes the toxic ammonia and nitrites from the water. In this phase you will need a filter media for these bacteria to colonize on that seldom requires any maintenance. There are several excellent products available today for biological filtration media such as filter mats, bio balls, Kaldnes and Springflo for example.  

The last component is a U.V. Light to get rid of the green water and reduce some parasitic and bacterial problems. This is the only predictable way to have clear water. There are many misconceptions about the use of U.V. Lights. Call if you need a detailed explanation of U.V. lights. 

To summarize this article you can never have to large of a filter but you can have to small of a filter.

Your filtration system will be greatly enhance your pond, resulting in the ability to handle a larger fish population while maintaining clear, clean, and healthy water.  If your pond is designed correctly with good filtration you should never have to drain your pond and clean it or continually add additives to maintain the pond. The surface of your pond is a huge biological chamber and every time you drain and clean the pond you start over again. I cannot count the number of calls we get every year from pond owners who had their ponds drained and cleaned only to suffer a fish loss, some lost them all. This is sad because it could easily be avoided if the pond was designed correctly with a good filtration system to remove all the waste from the pond on a continuous basis. 

Most filters over rate the size of pond they will actually clean, unless your favorite hobby is cleaning your filter. Remember you get what you pay for. 

What is your time worth? The last suggestion I have to make in this article is make sure you buy or build a filter that is easy to maintain, so you may spend your time enjoying your pond and fish. Call if you have filtration questions or Koi problems.

Have a great day, Dennis