Ph and Ta

[tony]

Thanks Vinny and Reese for picking up on this.  Not much more I can add.  I agree with WHY NOT regarding shocking with MPS over Dichlor if you have concerns with CYA.  Your weekly shock dose probably adds as much CYA as your daily dose over the long term, so using MPS could cut your CYA in half.  I have switched to MPS because I don't have to wait to use my spa, it is a complete shock and idiot proof (if you use too little chlorine to shock...you haven't shocked) and last, it adds less to CYA.

As far as bleach is concerned, it works....but....it voids warranties, you have to watch your pH always because its going to rise quickly, you have to be very careful adding it and its shelf life is short.  It is not for the faint of heart and not for the new user (anyone who tries bleach should be in full control of their chemistry and how to test it).  As I said, I use it in my pool (as Vinny does) along with trichlor tabs where it makes sense because of the larger volume of water and because CYA is something that has to be addressed in an outdoor pool.  I have experimented with bleach in my spa for a bit and quickly decided that the gains were very few, but the risks great.  Dichlor is by far the best chlorine for a spa, IMO, just because it is pH neutral, is quick dissolving and is easy to use.

There was one suggestion from the other forum that experienced bromine users may want to experiment with.  Shock weekly with bleach vs dichlor or MPS.  The high pH of bleach helps neutralize the low pH of bromine.  

BTW, there is a forum out there dedicated to sanitizing your POOL with bleach.  

[Chad]

 Your weekly shock dose probably adds as much CYA as your daily dose over the long term, so using MPS could cut your CYA in half.  I have switched to MPS because I don't have to wait to use my spa, it is a complete shock and idiot proof (if you use too little chlorine to shock...you haven't shocked) and last, it adds less to CYA.

  

Tony, I'm not sure exactly what CYA is. I test for it and know it's reccommended to keep it between 30-50 but that's about it. Can you explain exactly what it is and tell me why dichlor adds to it faster than mps?
Thanks.

[CapMorgan]

Why Not,

Here is some info for you on CYA

http://www.ppoa.org/pdfs/PrP_Cyanurics%20-%20Benefactor%20or%20Bomb.pdf

http://www.dsf.health.state.pa.us/health/cwp/view.asp?a=180&q=234664

CapMorgan

[Chad]

Why Not,

Here is some info for you on CYA

http://www.ppoa.org/pdfs/PrP_Cyanurics%20-%20Benefactor%20or%20Bomb.pdf

http://www.dsf.health.state.pa.us/health/cwp/view.asp?a=180&q=234664

CapMorgan

Thanks for the links CapMorgan. I'm going back to school for a moment. Excuse me......

[Chad]

Wow, thanks again for the links. I really do have a much better understanding of CYA. I think I finally found the culprit for my dichlor problems. I didn't know that dichlor is 57% CYA and that at a certain ppm, CYA actually starts to diminish the effects of chlorine. That explains why last month when my CYA was 40 I was getting much higher FC levels for a longer time opposed to this month with my CYA at 110.
I think it's time for a refill unless I feel like spending the extra money on dichlor. Times aren't that prosperous right now, so I better just dump it.

[tony]

To put in very simple terms, Cyanuric Acid (CYA) is like a series of little umbrellas that protect chlorine from the sun.  In an outdoor pool, the sun will diminish the available chlorine rather quickly, thus the need for CYA (aka stabilizer).  While chlorine will disappear from the water, CYA stays, something like TDS or calcium...the only way to dillute or eliminate is to change the water.  Now that we know that these little umbrellas don't disappear, when there are too many of them, the chlorine becomes overprotected and has a more difficult time doing its job of sanitizing.  In a pool, splashout, backwashing, etc help keep CYA levels down because you constantly add water.  In a spa, periodic water changes solve the problem.  You will find many articles regarding safe levels of CYA, but most public authorities recognize that 100 ppm should be max for a pool or spa.

In the small volume of water of a spa, all sanitizing methods have their good points and bad.  There is no perfect sanitizer and there is no perfect chlorine.  

[hottubdan]

To put in very simple terms, Cyanuric Acid (CYA) is like a series of little umbrellas that protect chlorine from the sun.  In an outdoor pool, the sun will diminish the available chlorine rather quickly, thus the need for CYA (aka stabilizer).  While chlorine will disappear from the water, CYA stays, something like TDS or calcium...the only way to dillute or eliminate is to change the water.  Now that we know that these little umbrellas don't disappear, when there are too many of them, the chlorine becomes overprotected and has a more difficult time doing its job of sanitizing.  In a pool, splashout, backwashing, etc help keep CYA levels down because you constantly add water.  In a spa, periodic water changes solve the problem.  You will find many articles regarding safe levels of CYA, but most public authorities recognize that 100 ppm should be max for a pool or spa.

In the small volume of water of a spa, all sanitizing methods have their good points and bad.  There is no perfect sanitizer and there is no perfect chlorine.  

Well put.

[Gomboman]

To put in very simple terms, Cyanuric Acid (CYA) is like a series of little umbrellas that protect chlorine from the sun.  In an outdoor pool, the sun will diminish the available chlorine rather quickly, thus the need for CYA (aka stabilizer).  While chlorine will disappear from the water, CYA stays, something like TDS or calcium...the only way to dillute or eliminate is to change the water.  Now that we know that these little umbrellas don't disappear, when there are too many of them, the chlorine becomes overprotected and has a more difficult time doing its job of sanitizing.  In a pool, splashout, backwashing, etc help keep CYA levels down because you constantly add water.  In a spa, periodic water changes solve the problem.  You will find many articles regarding safe levels of CYA, but most public authorities recognize that 100 ppm should be max for a pool or spa.

In the small volume of water of a spa, all sanitizing methods have their good points and bad.  There is no perfect sanitizer and there is no perfect chlorine.  

Very nice post. I wonder why a chemical manufacturer doesn't make a version of dichlor without CYA for spa users. I know Lithium Hypochlorite doesn't contain CYA but the available chlorine content is only 35%. Can't someone make 56% dichlor without CYA?