SACRIFICAL ZINC ANODES FOR SALT WATER POOLS
How it Works
The Sacrificial zinc anode protects all metal parts (heaters, lights, rails, etc.) from galvanic corrosion. Zinc anodes will sacrifice themselves and corrode before all other metals in the pool. Zinc anodes need to be replaced approximately every 4-5 years.
Reasons for using Zinc Anodes in chlorine-generated salt water pools
Any time you have different metals (copper, stainless steel, etc.) in a salt water pool, you create a battery. Some amount of current flows between the metals. The electrons that make up the current are supplied by one of the metals, giving up bits of itself in the form of metal ions to the pool water. This is called galvanic corrosion. Galvanic corrosion causes plaster discoloration and metal erosion. The best way to inhibit the effect of galvanic corrosion is to use a zinc anode. Zinc is a metal that gives up its metal ions faster than other metals in the pool. In other words, the zinc anode will erode instead of other metals (pool light, rails, heater, light niche, ladder, etc.). The zinc ions will not discolor the pool plaster. The zinc anode should be replaced after half of it has eroded.
Salt systems. We have received many questions regarding the use of alternative chlorine generation systems, referred to as "Salt Systems".To help answer them all we have listed some details below;
Do I have to add salt every month with a salt water chlorinator?
Salt should be added to the pool when necessary. Salt level may decrease after a heavy rain, backwashing, refilling, draining or excessive splash out.
Do I still need to use granular chlorine with my Salt water chlorinator?
The salt water chlorinator replaces the hassle of having to use granular chlorine. If the chlorinator is the correct size, then it's sufficient to sanitize the pool without adding granular chlorine.
How do I add salt?
Is it true that a salt water chlorinator provides chlorine-free water?
No, a pool treated by salt water chlorination is a chlorinated pool in which the chlorine is produced automatically. The salt under the effect of electrolysis, is transformed into sodium hypochlorite, a disinfectant.
Is it true that salt water chlorination is maintenance free?
While the salt water chlorinator prevents the user from needing to add chlorine to the pool on a regular basis, some maintenance, in regards to water balancing, will still need to be accomplished.
Check the water balance as usual. The water balance will be less threatened, because only pure chlorine is added to the water. All other forms of chlorine (tablets, powder, liquid, etc.) contain additives. In addition, chlorine levels can be stabilized easier with less dramatic fluctuations.
My pool is currently treated using bromide. Can I switch from bromide to salt water chlorination using the same water?
If there is still a large amount of bromide in your pool, we recommend that you wait for it to dissipate. It is ok to startup the chlorinator when there is a little bromide in the pool.
The remaining bromide in the pool will produce a white emulsion (chemical reaction). The remaining bromide will not harm the users, pool equipment or the pool.
What is polarity inversion on a salt water chlorinator?
Polarity Inversion is what salt water chlorinators use to periodically remove scale from the electrode plates. The controller will periodically change the direction of the cell current in order to eliminate the layers of scale that deposit on the electrode plates. This action maintains the cell. For very hard water, some chlorinators can shorten the polarity inversion time (e.g. 2.5 hours instead of 5 hours) so that the electrodes are cleaned more often.
Warning: shortening the polarity inversion time can wear the electrodes more than usual. This is why changing this parameter is reserved for the pool professional.
What type of salt needs to be used for salt water chlorination?
Salt only needs to be added when necessary. This may be necessary after heavy rains, backwashing and refilling, excessive splash out, etc. It's always important to test the salinity before adding salt to determine how much salt should be added.
Will salt from the salt water chlorinator deteriorate the metal components in my pool?
If the ladder is bonded properly to the rest of the pool equipment, corrosion will be minimal. Most cases of corrosion can be better explained by an incorrect water chemistry as opposed to the presence of salt.
Stainless steel is better adapted to resist salt than Galvanised steel. If corrosion appears in one year, it can be explained by incorrect water chemistry or bonding issue, not by the presence of salt alone.
Will there be any harm if someone swallows salt water in a salt chlorinated pool?
While the salt shouldn't have any effect on the person if a small amount is swallowed, please keep in mind that the water is chlorinated and chlorine should not be consumed.
Bob Charlton is a Certified Pool & Spa Operator and Inspector with the National Swimming Pool Foundation with 17 years of experience within the pool industry in Florida.