Hot Tub and Spa Chlorine
There are many ways to sanitize your hot tub or spa, how do you decide which one? There is chlorine, bromine, alternative sanitizers, chlorine generators, bromine generators, shock and so on. All have their place and some are better than others for a small water volume spa with hot water.
Sodium Dichlor
If you are going to use chlorine in your spa, this would be the choice. It is almost pH neutral (will not effect the pH of your spa) and dissolves quickly. However, it does have stabilizer (cynuric acid) which you don't want building up in your spa. If you drain your spa every 6 months then the cynuric acid buildup will likely not be a problem.
Trichlor
A great choice for pools, but for spas it disolves slowly, lowers the pH, has stabilizer, may cause bleaching of the shell if the trichlor tabls are in contact with the shell, and may leave a permanent water line ring.
Cal-hypo
Calcium hypochlorite is very popular for pools because it is relatively inexpensive. It includes calcium which can leave deposits on the spa equipment (heater and fittings) and can contribute to a calcium water line ring.
Liquid Chlorine
If you have it, use it but it raises the pH and is not the best choice for a spa with the water at higher temperatures.
Tags: Chlorine
June 27th, 2010 at 9:37 am
You want to avoid adding chemicals to your spa that effect the pH. Sodium Dichlor is a good choice as the sanitizer if you are going to drain and refill you spa or hot tub when the stabilizer exceeds 100. You can also use it as the shock treatment and use a saltwater chlorine generator to provide the continuous sanitizer. Do not use a pool shock in your spa as they are not buffered for pH and you may have drastic fluctuations in your pH if you do. A saltwater chlorinator does raise the pH but it is very gradual and if your fill water has a low pH there may be a perfect balance.