Pool Chemical Balancing, Draining Requirements
With so much positive buzz about swimming pool and hot tub saltwater chlorination systems, it can be easy to miss some of the negative aspects of this form of chlorination. Before you make the decision to convert your pool to saltwater, you need to understand a little bit about the risks associated with this alternative form of sanitizer delivery.
The first thing that you will notice is that the chemical balance process that you use for your pool or spa will change when you add a saltwater system to the pool. Where most swimming pools will tend to have a low pH due to the low pH of most traditional chlorine products, a saltwater pool will tend to have a high pH due to the chlorine produced from the salt system having a very high pH. This alone is not necessarily a problem since chemical balance is a part of regular pool and spa maintenance. The problem is that many pool owners mistakenly buy a salt system thinking that it does not require maintenance, and if corrective action to keep the pH down is not taken, then you have a recipe for disaster on your hands.
The next item to consider is how you will drain your pool when the time comes. Usually a swimming pool is pumped out to the curb in front of your house and then the water runs into the nearest sewer grate. Some larger urban centers are now beginning to ban saltwater swimming pool draining into the street. Many cities are implementing a bylaw which requires saltwater pool owners to pay to have their water trucked away, or choose to send the water into the sanitary drainage system for their house.
The final factor to consider when thinking about converting to saltwater is something called galvanic corrosion. This is the process where dissimilar metals are submerged in an electrolyte solution developing a current that travels in between metal components in the water. When submerged, these differing metals will develop a tiny potential electrical difference between them which is called “voltage”. Submerging dissimilar metals in saltwater is how you make a battery, and if action is not taken to prevent this from happening with your pool, then you will have a 25,000 gallon battery that operates 24/7 in your backyard – slowly eating away at your pool. Inside the pool and part of the pool equipment are all sorts of metals such as nickel, galvanized steel, copper and titanium. Since all of these metals are located in the saltwater, it is possible to develop a small electric charge across these different metals.
Salt chlorine generators do have the benefit of not dealing with liquid chlorine and salt can be easier on the eyes and leave your skin feeling silky soft when you get out of the pool. These benefits however are not worth potentially destroying your pool and equipment so be sure that:
- The pool is electrically bonded and all equipment such as the heater and pump have a bonding wire connected to the casing
- You install an inline sacrificial anode to mitigate the damage of galvanic corrosion
- You understand the relationship between pH and total alkalinity and how to keep these values within the ideal ranges
If you take these steps you can enjoy the benefits of saltwater while limiting the potential for damage and expensive repairs in the future.