Advantages of a salt system
Posted by mark on Monday, June 23 2008

Benefits of Salt Water Pools
Salt water pools used to be the exception, but now they are becoming a widely accepted method of water treatment in swimming pools. A lot of builders are now making salt water systems standard on their new pools.  Most equipment manufacturers have also become aware of the fact that salt water pools are not just a passing fad.  They are here to stay.
Why have salt water pools become so popular?
In this author's opinion, most people who consider themselves "sensitive" or "allergic" to chlorine are not reacting to the chlorine at all.  What is creating a problem is packaged pool chemicals and the additives and carriers in those chemicals.  Those same swimmers who claim allergic reactions to chlorine, typically experience no problems when they are in a salt water pool.  The answer isn't the absence of chlorine.  Salt systems create their own chlorine.  The answer is the absence of all the packaged chemicals and by-products in those chemicals.
What is the cost benefit of a salt water pool?
Most people do not buy a salt water pool system for the sole purpose of saving money.  They buy it for the increased swimmer comfort.  With that said, they do save quite a bit of money on pool chemicals, but it probably takes about 2-3 years before the system pays for itself. 
Here is the best rationale for buying a salt water system:  People spend $25,000 and up to build a beautiful pool, so doesn't it just make sense to spend about $1600 on the water quality.  After all, shouldn't the best thing about the pool be the water?  In the end, you get what you pay for.  A little money spent on the salt water system will allow the typical homeowner to enjoy their swimming experience so much more.
What is the down side to a salt water pool?
The only real problem we have seen is the fact that it does change the way you do your water chemistry and people are sometimes slow to adapt.  It is very important to follow directions carefully with regard to water chemistry.  Some pool owners have experienced problems trying to keep the pH down, but in our experience it is simply a matter of keeping up with the water chemistry and not letting the pH get too high before trying to adjust it.  Overall, the water chemistry does get easier, but there is a small learning curve
Salt Water Pools - What's Different?
What's the difference between a saltwater pool and a pool maintained with packaged chlorine?
Salt water pools used to be the exception, but now they are becoming a widely accepted method of water treatment in swimming pools. A lot of builders are now making salt water systems standard on their new pools.  Most equipment manufacturers have also become aware of the fact that salt water pools are not just a passing fad.  They are here to stay.
Lower Chlorine Levels -
Saltwater Pools - 0.5 to 1.0 ppm chlorine
Traditional Pools - 3.0 - 10.0 ppm chlorine
No "Chemical Bath" Feel
NO packaged chlorine needed.
NO algaecides needed
NO soda ash or baking soda
Better Swimmer Comfort
By eliminating the need for the harsh chemicals, you eliminate the source of the irritation that plagues swimmers in most pools.
Controlled Stabilizer Levels
If you are using chlorine tablets, you are adding 1 lb. of stabilizer for every 2 lbs. of tablets you put into your pool.   Your stabilizer level rises to over 100 ppm and your chlorine becomes ineffective and yellow algae and poor sanitization results. 
With a salt system, you add stabilizer as needed and are able to keep the level low.  Your chlorine remains VERY effective and you need much less in the water to do the job (see above).
On commercial pools, state code requires you to drain pools when the stabilizer level exceeds 100 ppm.  The salt system avoids this problem.
Superior Algae Control
Saltwater pool systems virtually eliminate algae problems.  This is because the chlorine in the pool is not inhibited by high stabilizer levels
How Does a Salt Water Pool System Work?
How a Salt System Operates
Salt systems have three main components.
Salt
The first component is plain old salt.  You have to have a minimum level of about 3000 parts per million of salt in the pool water.  Salt makes the water conductive so that the electricity can pass between the plates in the cell.  If the salt level goes too low, then the chlorine production simply stops.  Salt is also the raw material from which the chlorine is produced.
Control Box
The control unit is a device that sends power to the salt cell.  The unit controls how much chlorine is produced by regulating how long the power is applied to the cell.  If you turn the control knob way down, then the unit might apply power to the cell only 25% of the time, thereby producing less chlorine.  If you turn the control knob up, then the unit would apply power to the cell for a longer period of time.  The amount of power applied to the cell does not increase or decrease. 
The control unit will often sense the level of salt in the pool and indicate the need to add more salt.
Self cleaning units have a feature built into the unit that reverses the polarity of the voltage through the cell in order to clean any scale buildup off of the cell plates.
Salt Cell

The salt cell is a series of plates with opposite charges in a cell.  As the water passes between the plates, electrolysis takes place, releasing the chlorine in the salt. 
 
1.  Keep the proper level of salt and stabilizer in the pool
Most salt water chlorinators require a 2500 - 3000 parts per million salt concentration in the water.  This can barely be tasted in the water, but provides enough salt for the salt cell to produce the chlorine needed to maintain the pool.
If the salt level drops too low, the system will not be able to produce chlorine.  Most systems have some sort of indicator to show low salt levels in the pool.  The answer to low salt levels is to add rock salt to the skimmer and let it dissolve into the water.
NOTE:  If the system indicates a low salt level, be sure to test it with a salt test kit before adding salt.  If a salt cell is failing or is scaled it may give a false low salt indicator.
It is also important to have a good stabilizer level (30 - 50 ppm) in the pool or the sunlight will burn up the chlorine and the saltwater system will not be able to keep up with the demand.
2.  Adjust the control knob on the salt system
The salt system has a setting that controls the amount of chlorine that is generated.  This can be adjusted to keep the production of chlorine in line with the demand.
3.  Make sure the pool is running long enough to produce adequate chlorine
The timers on the pool should be set to run during the hottest daylight hours, preferably from at least 10 am to 6 pm during the summer.  This is when your chlorine usage is highest.  The system will only produce chlorine while the pump is running so it is important to run the pool long enough.
Shocking a Pool (Superchlorination)
If the chlorine reading gets too low then it is important to superchlorinate the pool in order to quickly raise up the chlorine level to avoid unsanitary water.  The salt system should be sized to provide sufficient chlorine output, but in the event of very heavy chlorine demand (swim party, heavy rains, etc.) it might be necessary to supplement the chlorine feed with a manual shock (this is a rare occurence).
It is important to use only as much granular chlorine as is needed.  Many salt system owners are sensitive to heavy amounts of packaged chlorine with all its byproducts.