Thursday, May 14, 2009

 

Phosphate in swimming pool water - the root of algae problems

Phosphate is fast becoming recognized as the major cause of algae in swimming pools. This summer has seen some of the highest recorded phosphate levels in swimming pools across Australia and New Zealand.

Some of this high level of phosphate has been attributed to summer drought related dust fallout, and an increase in the phosphate levels of several common fertilizers. For many years phosphate and nitrate runoff from farms has been blamed for the deterioration of our many lakes and waterways, now the problem has crossed into our swimming pools.

For pool owners, the biggest concerns from high phosphate levels are rapid chlorine consumption and stubborn, repeat algae problems. In order to maintain healthy water quality, it is important to remove phosphate from the pools water. Once it has been removed, regular maintenance can prevent the level from becoming a problem again and also aid in better chlorine performance and efficiency, reduced chlorine consumption, and no algae problems.

Phosphate and nutrients are required by all living organisms, including algae, to survive and flourish. It is commonly accepted that increasing the chlorine level and reducing the phosphate in swimming pool water results in less algae problems.

But how are they related, and what can be done to remove phosphate from swimming pool water? Phosphate is introduced to pool water from a variety of sources including runoff from lawns and gardens, pool fill water such as bores, dust, suntan oils and leaves. With time, all of these sources will cause a build-up and increase in the concentration of phosphate in the pools water. Algae spores are continually being introduced to the pool attached to dust and leaves. They only require nutrients and water to quickly multiply and become a threat to the pools water quality due to rapid consumption/destruction of available chlorine.

For decades chlorine has been used not just as a pool sanitizer, but it is also effective as a short lived algae killer. Traditional treatment has included "shock" dosing the pool with three to five times its regular daily chlorine dose; this is effective at killing off almost all visible algae. While this effectively kills the algae, it does not do anything to address the condition that allowed the algae to flourish in the first place. When the chlorine level returns to normal to algae will begin growing again. Therefore preventing the algae from recurring requires that the chlorine concentration is maintained at the higher level, the water is removed from the pool, or water conditions are changed to become less favourable for algae growth.

Traditionally, phosphate levels have been ignored, while attempting to remove dead algae by filtration. Given wet algae weighs 1000 times more than the phosphate needed to feed it, this is not the most effective way to do this. Also as the algae are trapped in the filter, it releases a certain amount of trapped phosphate back into the water. The most effective traditional treatment is "super chlorination" or ten times the normal daily dose, effectively bleaching the algae white and killing it. This is followed by a "floc" with aluminium salts, before vacuuming the settled dead algae to waste. Up until recently, none of the traditional treatments for algae targeted the real cause of the algae problem.

While chlorine was effective as a treatment for visible algae, prevention was not addressed. In swimming pools there are two effective chemical treatments for removing phosphate from swimming pools: lanthanum compounds and aluminium compounds. In sewage and effluent treatment ponds, iron compounds are used effectively, however these are undesirable in swimming pools due to the staining they cause. Aluminium compounds are more effective in pools with a high level of phosphate build-up, in the range of greater than 1000ppb (parts per billion); however they require vacuuming to waste after treatment. They will effectively remove phosphate down to 500ppb, but cannot remove phosphate below 100ppb which is required for effective algae control. Aluminium compounds are relatively cheap, and therefore suitable for removal of a large percentage of phosphate accumulated in the pools water. Lanthanum products are a potent and specific phosphate remover. They are best suited to maintaining low levels of phosphate in pools where performance and convenience are important. They are easier to use and apply than aluminium products and do not require vacuuming to waste after their application. However they are more expensive and best suited for pools with less than 2000ppb accumulated phosphate. One of the main advantages of lanthanum is that its ability to form lanthanum phosphate is not affected by the pools water balance. A small amount of lanthanum compound will cause the phosphate level to drop below 100ppm, while concentrations of below 10ppb are easy to maintain. Lanthanum compounds work by lodging in the pools filter media or cartridge, slowly dissolving to lightly coat the filter media. As phosphate rich water passes over the lanthanum crystals, they chemically attach themselves to the phosphate - forming lanthanum phosphate. Lanthanum phosphate is not suitable as a nutrient, and binds into larger particles so it can be removed by the pools filter medium. Large quantities of lanthanum can be stored in the filter without clouding the pools water. To conclude, phosphate removal is the secret to maintaining algae free, quality swimming pool water, while allowing other chemicals to work at their optimal level. Additional algae insurance, is the use of a preventative, "long life" copper based algaecide to be used in conjunction with regular testing for phosphate. While phosphate will accumulate in a pool naturally, there are steps pool owners can take to prevent excessively high levels. - Do not allow runoff from gardens and lawns to enter the pool - Remove leaves from the pool regularly and promptly - Apply a lanthanum compound phosphate remover regularly - Have the pools water tested by a professional.
Mike Brunt is a director of Aqua Clear Products and has been involved in the New Zealand pool industry for 15 years with specialist skills in filtration, heating and water chemistry. for more information see www.aquaclear.co.nz for all your pool equipment needs More information on treating pool alage

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Thursday, April 30, 2009

 

Pool Stains

Stains on your pool plaster can greatly reduce the aesthetic of your pool. There are several chemicals available that claim to rid your pool of stains, however we find that these are generally used to prevent stains, especially in areas with high concentrations of metal in the water.

Here are a couple of links to products that are designed for stains.

http://www.intheswim.com/Pool-Chemicals/Pool-Stain-Removal-and-Stain-Prevention-Chemicals/The-Sapphire-Stuff-by-Jacks-Magic/

http://www.saveonpoolsupplies.com/shopping/product.aspx?productid=56&e5=Y&e6=swimming_stain&pp=Y&keyword=swimming_stain


Sequestering agents and or “stain out” are very commonly used right after the initial plaster job to aid in the balancing of the pool and protect the shell against staining.

These products are pretty pricey, as you can see these products can run from $15-$30 for 1 qt as a result they are mainly used when the pool is initially installed or plastered.

The prices for these products online are usually pretty competitive and sometimes better then retail and can be purchased and administered per the directions on the bottle. These chemicals can be purchased and administered, however in my experience I haven’t found them to do much once there is a stain. Once staining occurs the most effective solution in my experience is to perform an acid wash. You can spend all the money you like on a barrage of chemicals with no guarantee as to whether they will achieve the desired result. Over time you will inevitably need to acid wash and replaster due to the nature of chemicals coming into contact with pool equipment and plaster, and each pool is different with respect to this issue.

Here is a little more information on the above:

Sequestering agents. A sequestering agent is a chemical that combines with metal ions to help keep them in solution and prevent them from falling on the pool’s surface and leaving a stain, according to NSPI.
These products, which can also be used to control scale buildup, are used mostly for prevention. They won’t remove old, existing stains (that’s a job for a dedicated stain remover), but they will work on potential stains and keep them from becoming visible.
Source water can sometimes be rife with metals, so the use of a preventive sequestering agent is critical, say service professionals.
“In some of our rural areas, our customers have well water with naturally occurring metals,” says Suzanne Heim, marketing director at Classic Pool & Spa, a retailing/service company in Gladstone, Ore. “So we have to do a lot of metal control.”
Eastergard notes that metals often are a problem even if they’re not in the source water. For example, iron can find its way into a pool if there is a notable amount of construction in the area or if old pipes are being dug up for renovation. He points out that a sequestering agent will keep the staining at bay, which is important because iron can wreak havoc on a pool’s surface when certain chemicals are added to the water.
“If you get iron in your water and then shock it, it will turn the steps yellow-brown,” Eastergard says. “Then the customer thinks they’re dirty and you’re not cleaning the pool. This stuff just plates onto the shell material, and it can plate onto the plastic fittings.”

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Thursday, April 3, 2008

 

Spa Draining

Periodic complete draining of spa water is the most important component of proper spa water maintenance. High bather loads and the hot water conditions cannot be handled over long periods of time without draining the spa. The following is a dumping formula that is a good guideline to go by.

First, divide your total spa gallons by 3. Divide this result by your Bather Load, which is the average number of bathers per day. The final result is the estimated number of days between water changes recommended for a properly maintained spa or hot tub.
Example,

Residential:

600 gallon spa / (Divided By) 3
___________________ = 100 Days

2 People per day bather load


Once you have determined how often your spa needs to be drained you may perform the draining on your own, or you can have LA Pool Guys perform this service for you at an additional cost. If you choose to drain your spa on your own you can purchase a sump pump at a local hardware store to speed up the draining process.

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Tuesday, April 1, 2008

 

LA Pool Guys Updates and Information

Welcome to the News Section of LA Pool Guys. Check back often for new posts. We are constantly striving to be the number one pool service company in the Los Angeles and Long Beach area.

On this site in the near future, you will be able to find information regarding pool service, energy efficiency of pool equipment, repair information, commercial property information, Health Department regulations, and much more!

Thank you for your interest in LA Pool Guys - Please Bookmark this page and check in often!

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