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Before purchasing a pond fountain, it’s important to educate yourself as to the quality of the many types of fountains available on the market. Today we’ll be talking about the differences between oil-less pumps and pumps containing oil.

Many fountain suppliers will proudly proclaim in their advertising that their fountain pumps do not contain any oil. They try to make it sound as if a pump with no oil is a good thing when in fact it is the worst thing they could say to someone knowledgeable about pumps and pond fountains.

Pumps that do not contain an oil bath generally have what is called lip seals. We have been in the pond fountain industry for more than 16 years and through personal experience we have learned that lip sealed pumps do not and will not last very long in dirty or cloudy pond water conditions. A lip seal is a stationary seal that is pressed into the pump housing and the shaft of the pump turns against the seal as the pump runs. When particulates from the pond water collect at the contact point between the seal and the pump shaft friction is created causing a “grinding effect” that wears a ring into the shaft surface. Once the shaft is worn down by this grinding effect then water migrates thru the ring worn into the shaft and past the seal into the pumps electric motor causing a major malfunction of the motor. There is no repair or recovery from this problem and the pump must be disposed of and replaced. Typical life expectancy of a fountain built using a sump pump with lip seals is about 1 to 1-1/2 years or less.

Alternatively, most industrial and commercial grade fountains built using submersible pumps contain high quality heavy-duty silicon carbide on ceramic face seals, rather than lip seals, and do contain oil. These industrial grade pumps contain a few ounces and up to a liter of common mineral oil. The purpose of the oil is not for lubrication but rather to keep these high-end seals moist and pliable. Silicon carbide on ceramic face seals are a two part seal with the outer half of the seal pressed into a pump seal housing and the inner half pressed onto the pump shaft so that when the shaft turns the two faces of the seal run against each other. In this type of pump there is NO FRICTION OR WEAR on the pump shaft from running against a stationary seal.

Silicon carbide on ceramic face seals are an industrial grade seal that creates a waterproof barrier between the water and electrical compartments in the pump. They are designed to handle your ponds dirty water conditions. The pumps we use in construction of our Eagle Fountains have not one but two sets of these silicon carbide face seals which means that your pump will last many times longer than a sump pump with lip seals in dirty pond water conditions.

Most fountain manufacturers today use “oil-less” sump pumps with lip seals to construct their fountains because the pumps are inexpensive allowing the manufacturer to maximize profits but these types of pumps are in our opinion not in the best interest of the end user for pond fountain applications. If you are shopping for a pond fountain and the suppliers’ pumps are advertised as “oil-less,” then realize that they are a one-use throwaway sump pump the same as you could buy at your local hardware store for about $50.

If you have any questions, please do not hesitate to contact us!