CLARITY OR ALGAE PROBLEMS?

Dear Customer:

 

I encourage you to read the information below on pool filter types and capabilities; I believe you will find it very enlightening especially if you already own a sand filter. I can’t explain enough the importance of a good filtering system on your swimming pool. Here in Arizona, we have the most severe of all weather conditions compared to other swimming pool markets, and what works well in other areas may have problems working here in the desert.

 

Most swimming pools do not turn green or cloudy if there is chlorine present in the water. So if your pool has a history of turning green or staying cloudy with a chlorine residual in the water, I would seriously suggest changing and upgrading the sand to Zeobrite (www.zeotechcorp.com), or better yet, replace the sand filter with a Cartridge or Diatomaceous Earth (D.E.) filter, and solve the problem. The problem is not that there are insufficient chemicals present, but that the sand cannot filter out the smaller particles of contaminants in the water.    

 

As mentioned below, a Cartridge or D.E. filter is 15 times more efficient than a sand filter… so one night of running a D.E. filter (8 hours) will give you the same effect as running a sand filter non-stop for 5 days…

 

Again, please read the enclosed bulletin on filters below.

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SWIMMING POOL FILTERS: TYPES AND CAPABILITIES

 

Some of the most commonly asked questions regarding pool filters are:

1. What kinds are there?

2. What are the differences?

3. Is one more efficient than another?

4. When installing a new filter or replacing an old one, which filter do you recommend that I use?

We offer the following information to answer these questions and hope it may be helpful to you in understanding the issues and our recommendations.

 

SAND FILTERS               

                                         

The outside of this type of filter is usually made out of fiberglass or stainless steel, and it is partially filled with silica sand. As water circulates for the pool through the filter, water enters at the top and percolates downward, leaving most of the oils, debris, and other impurities trapped in the sand, thus allowing clean water to return to the pool. The filter is usually backwashed one or two times per month, a process that reverses the flow of water through the filter.  This lifts most of the contaminates from the sand and flushes them out the backwash line, along with a significant amount of water. The efficiency of any filter is measured by micron size (one millionth of a meter) by the largest micron that can pass through the filter without being caught.  Sand filter efficiency is 40-50 microns.  Eventually the filter can become overburdened from the minerals in the water and from the volume of debris (dirt, dead algae and bacteria, etc.) remaining in the sand, causing the sand to become hard and compacted. This reduces water flow throughout the system and can cause cloudy water, poor heater operations, and increased wear and tear on your equipment. Approximately every 3-5 years, the old sand will need to be removed and new sand added. Under some circumstances, the sand must be changed every year (painted pools, and some fiberglass pool surfaces plug up the sand very quickly) .

 

Drawbacks for sand filters include:

1. Longer filtration times are required.

2. Filtration efficiency is 40-50 microns.

3. More specialty chemicals are required to keep the pool clean and clear.

4. Uses high volumes of water for backwashing.

5. Filter maintenance is often neglected, since sand filters are sometimes sold as “maintenance free.”

CARTRIDGE FILTERS

Cartridge filters come in various shapes and sizes.  The filter canisters or tanks are made of stainless steel, hard plastic or fiberglass. There may be as few as one or as many as fifteen cartridge elements inside a cartridge filter. The cartridge elements are cylindrical, and made of a paper, cloth-like fiber.  As the water passes through the elements, impurities are collected on the element material. Cartridges remove smaller debris from the water than sand filters; its micron rating is about 20 microns. This filter is cleaned periodically depending on pressure by removing the elements from the canister and hosing it off using a water hose.

 

Drawbacks for cartridge filters include:

1. Most cartridge filters are undersized for the pool they are on.

2. The manually disassembling for filter cleaning is tedious and difficult for some people.

3. The filter elements need replacement (oils and impurity can plug and even crush the element)

4. Since the water is never removed through backwashing the pool hardness and total dissolved solids become extremely high. (Your pool needs to be drained more often)

 

DIATOMACEOUS EARTH (D.E.) FILTERS

D.E. filters are made of hardened plastic, fiberglass, or stainless steel. The elements inside consist of a series of plastic grids covered with a cheesecloth-like fabric. A white powder known as D.E. is added through the skimmer and mixes with the water as it heads for the filter. As the water passes through the filter, the D.E. powder coats the outside of the elements. This coating traps microscopic impurities which cannot be trapped by either a sand or cartridge filter and therefore provides better water clarity. The filter is usually backwashed every 3-5 months by reversing the flow of the water which removes the dirt and the D.E. out the backwash line.  The efficiency rating of a D.E. filter is about 3 microns. This means you can filter anywhere from 15% to 50% less per day, which results in reduced electric bills and extended motor life.

 

Drawbacks for D.E. filters include:

1. Each time you backwash or clean a D.E. filter, you need to re-add D.E. powder to the skimmer.

2. The filter should be disassembled and cleaned twice per year. The manual disassembly for filter cleaning is tedious and difficult for some people.

3. The grid elements need replacing (oils and impurities can plug and even crush the element).