- May 23, 2015
- 25,718
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Drd,
Clearly there some significant gaps in the research you have uncovered regarding chlorine and chlorinated pool products. So let me take your assertions one at a time -
Yes, there are many indoor and commercial/public pools that are required by law not to use CYA because of their public health codes and/or pools that choose to operate without CYA because they use automated chemical dispensing systems (such as ORP controlled chlorine injectors). They are also commercial pools and NOT residential pools so they can operate using a much higher feed rate of chemicals. Because of their setups, they will typically operate pools with 1-2ppm FC and no CYA. That produces a hypochlorous acid (HOCl) concentration 14 times higher than a residential pool which maintains a 7% FC/CYA ratio. A pool running 1.5ppm FC and no CYA will have 0.73ppm HOCl in it which is incredibly harsh on swimmers. You are almost certain to smell the production of chloramines on your skin and bathing suits with HOCl concentrations that high not to mention bleached out and faded swim suits and hair.
Yes, CYA build up is a problem and TFP teaches people to clearly monitor and keep their CYA in check. The easiest way to do that is to set your CYA level using either granular or liquid stabilizer and then use liquid chlorinating product to maintain an FC/CYA ratio of 7.5%. Doing that produces a hypochlorous acid concentration of ~0.055ppm which is more than enough to inactivate pathogens (bacteria and viri) as well as keep algae at bay. Once a pools CYA level is set, the only way CYA can be added is through pool owner negligence in not understanding the effects of their chemical additions.
CYA does not "restrict" chlorine. CYA is a chlorine buffer that holds chlorine in reserve and will protect it from UV photolysis. What CYA does is alter the ratio of active chlorine (hypochlorous acid and hypochlorite) to reserve chlorine (chlorine bound to CYA). Once the active chlorine concentration drops too low from a high CYA level, that is when algae and pathogens can flourish. Even with a CYA of 200ppm one could theoretically add enough chlorine to achieve an FC/CYA ratio of 7.5% and the water would be sanitary. The problem with high CYA is that the FC levels required become impractical to maintain and that is when problems start.
TDS is irrelevant to pools. TFP teaches pool owners to measure all of their water parameters separately and so TDS is of no importance. TDS was used in the days before high quality test kits were easily available and it was a proxy for the build up of chemicals like CYA in the pool water. TDS all by itself is a meaningless quantity.
The foundational teaching of TFP is understanding the effects of chemical additions to your pool water and testing your own pool water to know exactly what is in it and what needs to be added. Without a high quality test kit, you have to rely on others to tell you what is in the water (i.e., Pool Stores) and we have tens of thousands of pool owners who will attest to the low quality and contradictory results obtained at most Pool Stores.
As for stock piling chemicals, the chemicals I have on hand at home are muriatic acid....that's it. People who chlorinate their pools manually will keep bleach and acid on hand. Depending on the area of the country one lives in, there may be a need to raise pH and that can be done with washing soda or borax. All the chemicals required for a pool can be easily found in a grocery store or hardware store.
There is no clinically significant dermal absorption of salt by the human body. Pools that use salt water chlorine generators maintain salt levels at 3500ppm. Ocean salinity is ~ 35,000ppm. If dermal absorption of salt were a key health issue, humans would have died long ago from exposure to sea water.
SWG's do represent a large upfront cost but, when compared against the purchase of liquid chlorine over the life of the SWG cell, you simply find that the entire cost of the unit is basically the same as buying all of that liquid chlorine up front. My SWG has lasted 4 years so far and is in perfect working order; we have had members will cells that have lasted 10 years. The life of cell is impacted by how much it is used (they typically are rated at an 8-10k hour lifetime) and how well water balance is maintained relative to calcium scaling (calcite saturation index or CSI). In a properly balanced pool, SWG's will last a long time.
pH rise in a swimming pool is entirely dominated by CO2 outgassing from the water as pool water is over-saturated with carbonate alkalinity. When people report that SWG's caused a rise in pH it is mainly because they were so used to using acidic chlorine products (trichlor tablets and dichlor powder) that their pools pH and TA were kept low from that. With the SWG replacing those acidic sources of chlorine with a net-neutral pH source, the rise in pH caused by natural outgassing of CO2 becomes dominant and regular acid additions are needed to keep the pH in check. Even if you factor in the cost of additional acid, manual chlorination with liquid chlorine is equivalent in cost to running an SWG.
Cal-hypo adds calcium hypochlorite, calcium chloride, calcium carbonate and calcium hydroxide to pool water. It is a very high pH source of chlorine and most people that use it find that it causes water cloudiness for about 24 hours after adding it. A cal-hypo puck grinder and feeder might avoid the water scaling issues (for a time) but you are still adding all of those chemicals and the calcium hydroxide and carbonate will raise both TA and pH requiring regular acid additions to bring them down. Given Arizona's very high pan evaporation rates and high pH and CH fill water, you will more than likely need A LOT of acid on hand to keep the pH in check and your calcium hardness build up will be quite high. That alone will require you to either spend more money on RO treatments (which are not cost effective for most pool owners) or do significant water exchanges to bring the CH back into line.
At the end of the day, you can do as you wish with your pool but I can tell you quite honestly that what you are proposing to do will end in failure. You can either choose to believe what tens of thousands of pools owners have empirically determined to be the best way to manage their pools (Trouble Free Pool Care Method) OR you can choose to go off on your own and let chips fall where they may.
Here are some links for further reading that will hopefully shed some light on those gaps in your current research -
Certified Pool Operator (CPO) training -- What is not taught
Pool Water Chemistry
Economics of Saltwater Chlorine Generators
Clearly there some significant gaps in the research you have uncovered regarding chlorine and chlorinated pool products. So let me take your assertions one at a time -
Yes, there are many indoor and commercial/public pools that are required by law not to use CYA because of their public health codes and/or pools that choose to operate without CYA because they use automated chemical dispensing systems (such as ORP controlled chlorine injectors). They are also commercial pools and NOT residential pools so they can operate using a much higher feed rate of chemicals. Because of their setups, they will typically operate pools with 1-2ppm FC and no CYA. That produces a hypochlorous acid (HOCl) concentration 14 times higher than a residential pool which maintains a 7% FC/CYA ratio. A pool running 1.5ppm FC and no CYA will have 0.73ppm HOCl in it which is incredibly harsh on swimmers. You are almost certain to smell the production of chloramines on your skin and bathing suits with HOCl concentrations that high not to mention bleached out and faded swim suits and hair.
Yes, CYA build up is a problem and TFP teaches people to clearly monitor and keep their CYA in check. The easiest way to do that is to set your CYA level using either granular or liquid stabilizer and then use liquid chlorinating product to maintain an FC/CYA ratio of 7.5%. Doing that produces a hypochlorous acid concentration of ~0.055ppm which is more than enough to inactivate pathogens (bacteria and viri) as well as keep algae at bay. Once a pools CYA level is set, the only way CYA can be added is through pool owner negligence in not understanding the effects of their chemical additions.
CYA does not "restrict" chlorine. CYA is a chlorine buffer that holds chlorine in reserve and will protect it from UV photolysis. What CYA does is alter the ratio of active chlorine (hypochlorous acid and hypochlorite) to reserve chlorine (chlorine bound to CYA). Once the active chlorine concentration drops too low from a high CYA level, that is when algae and pathogens can flourish. Even with a CYA of 200ppm one could theoretically add enough chlorine to achieve an FC/CYA ratio of 7.5% and the water would be sanitary. The problem with high CYA is that the FC levels required become impractical to maintain and that is when problems start.
TDS is irrelevant to pools. TFP teaches pool owners to measure all of their water parameters separately and so TDS is of no importance. TDS was used in the days before high quality test kits were easily available and it was a proxy for the build up of chemicals like CYA in the pool water. TDS all by itself is a meaningless quantity.
The foundational teaching of TFP is understanding the effects of chemical additions to your pool water and testing your own pool water to know exactly what is in it and what needs to be added. Without a high quality test kit, you have to rely on others to tell you what is in the water (i.e., Pool Stores) and we have tens of thousands of pool owners who will attest to the low quality and contradictory results obtained at most Pool Stores.
As for stock piling chemicals, the chemicals I have on hand at home are muriatic acid....that's it. People who chlorinate their pools manually will keep bleach and acid on hand. Depending on the area of the country one lives in, there may be a need to raise pH and that can be done with washing soda or borax. All the chemicals required for a pool can be easily found in a grocery store or hardware store.
There is no clinically significant dermal absorption of salt by the human body. Pools that use salt water chlorine generators maintain salt levels at 3500ppm. Ocean salinity is ~ 35,000ppm. If dermal absorption of salt were a key health issue, humans would have died long ago from exposure to sea water.
SWG's do represent a large upfront cost but, when compared against the purchase of liquid chlorine over the life of the SWG cell, you simply find that the entire cost of the unit is basically the same as buying all of that liquid chlorine up front. My SWG has lasted 4 years so far and is in perfect working order; we have had members will cells that have lasted 10 years. The life of cell is impacted by how much it is used (they typically are rated at an 8-10k hour lifetime) and how well water balance is maintained relative to calcium scaling (calcite saturation index or CSI). In a properly balanced pool, SWG's will last a long time.
pH rise in a swimming pool is entirely dominated by CO2 outgassing from the water as pool water is over-saturated with carbonate alkalinity. When people report that SWG's caused a rise in pH it is mainly because they were so used to using acidic chlorine products (trichlor tablets and dichlor powder) that their pools pH and TA were kept low from that. With the SWG replacing those acidic sources of chlorine with a net-neutral pH source, the rise in pH caused by natural outgassing of CO2 becomes dominant and regular acid additions are needed to keep the pH in check. Even if you factor in the cost of additional acid, manual chlorination with liquid chlorine is equivalent in cost to running an SWG.
Cal-hypo adds calcium hypochlorite, calcium chloride, calcium carbonate and calcium hydroxide to pool water. It is a very high pH source of chlorine and most people that use it find that it causes water cloudiness for about 24 hours after adding it. A cal-hypo puck grinder and feeder might avoid the water scaling issues (for a time) but you are still adding all of those chemicals and the calcium hydroxide and carbonate will raise both TA and pH requiring regular acid additions to bring them down. Given Arizona's very high pan evaporation rates and high pH and CH fill water, you will more than likely need A LOT of acid on hand to keep the pH in check and your calcium hardness build up will be quite high. That alone will require you to either spend more money on RO treatments (which are not cost effective for most pool owners) or do significant water exchanges to bring the CH back into line.
At the end of the day, you can do as you wish with your pool but I can tell you quite honestly that what you are proposing to do will end in failure. You can either choose to believe what tens of thousands of pools owners have empirically determined to be the best way to manage their pools (Trouble Free Pool Care Method) OR you can choose to go off on your own and let chips fall where they may.
Here are some links for further reading that will hopefully shed some light on those gaps in your current research -
Certified Pool Operator (CPO) training -- What is not taught
Pool Water Chemistry
Economics of Saltwater Chlorine Generators
<a vicious pro-vaccinator too, lol>
