pool school swcg question

[costablanca blue]

Hello All,

I just read the guidelines on poolschool for swcgs and was interested to see the recommended TA figures at 60 to 80ppm. This appears to be a little lower than normally recommended for non-swcg pools. Can somebody please explain the reason for this?

I have experience looking after a few swcg pools but wasn´t aware of the need for such a low TA.

Thanks in advance :?

 

[jblizzle]

Sure.

A SWG inherently drives the pH up due to conditions within the cell. By lowering the TA, this should help to stabilize the pH so it will not rise as quickly.

One could easily make the same argument for pools with spillovers or water features that are run a lot.

 

[bacevedo]

I was curious about that, too, thanks for the info.

Now a related question. What happens if the TA gets below that range? I am always having to add acid to lower my pH and my TA is now within range. I expect that it will be low at some point due to always adding acid. What's the concern with a low TA?

 

[costablanca blue]

Sure.

A SWG inherently drives the pH up due to conditions within the cell. By lowering the TA, this should help to stabilize the pH so it will not rise as quickly.

One could easily make the same argument for pools with spillovers or water features that are run a lot.

Thanks for the reply. I checked a salt water pool today and the readings were 95 TA and 7.5pH. Normally I wouldn´t add acid yet, but would the experts on here be lowering the TA with those readings?

 

[JasonLion]

bacevedo, please ask questions in your own topic.

 

[jblizzle]

Ideally you would want the TA a little lower if you are seeing a pH rise. It does not make a huge difference if you lower the pH now or wait for it to rise some more.

 

[costablanca blue]

Ideally you would want the TA a little lower if you are seeing a pH rise. It does not make a huge difference if you lower the pH now or wait for it to rise some more.

OK think I understand. I don´t have a particular problem with pH rise, although as you said it always rises with a swcg. However, if I was to lower the TA to 80 it would slow down the process of increasing pH and presumably lessen the quantity of acid I use?

Many thanks for your replies jblizzle. If you were closer I´d buy you a beer

 

[RobbieH]

I'd go more, down to the 60-70 range. (actually, I did, but I recommend the same for you )

 

[costablanca blue]

I'd go more, down to the 60-70 range. (actually, I did, but I recommend the same for you )

If I find a calcium problem on a pool surface I usually decrease TA to just below 50ppm to clear the build up of calcium, then increase TA again once it´s disappeared.

I´m not disbelieving you people, and I understand that swcg pool chemistry is different, but the 60 figure sounds awfully close to the 50 I´ve always used to clear calcium. I always understood that if you leave TA below 50 that eventually you´d lose the grouting between the tiles.

I guess you are recommending 60 though and not 50 but Í´ll have to do my calculations correctly to make sure I don´t overdo the acid :|

 

[RobbieH]

You can go to 70 and see what that does for you first.

 

[costablanca blue]

You can go to 70 and see what that does for you first.

will do robbie. ps what does built in 1957 refer to?

 

[RobbieH]

The year my pool was built.

 

[costablanca blue]

The year my pool was built.

wow, that must have been built well! guess you need a pool over there with this heatwave you´re experiencing.

 

[RobbieH]

It's a cool wave this week. But that'll change again next week, back to triple digits.

 

[costablanca blue]

It's a cool wave this week. But that'll change again next week, back to triple digits.

that´s in great condition. you certainly build well on your side of the pond!

our gunite pool which is 10 years old sunk by half an inch last year. luckily it hasn´t cracked, yet.

 

[jblizzle]

I'd go more, down to the 60-70 range. (actually, I did, but I recommend the same for you )

If I find a calcium problem on a pool surface I usually decrease TA to just below 50ppm to clear the build up of calcium, then increase TA again once it´s disappeared.

I´m not disbelieving you people, and I understand that swcg pool chemistry is different, but the 60 figure sounds awfully close to the 50 I´ve always used to clear calcium. I always understood that if you leave TA below 50 that eventually you´d lose the grouting between the tiles.

I guess you are recommending 60 though and not 50 but Í´ll have to do my calculations correctly to make sure I don´t overdo the acid :|

You have to keep the other parameters in mind ... specifically the CSI. So if you maintain a lower TA, you may need to increase the CH some or just keep the pH a little higher so the CSI does not get too negative which could eventually cause the grout problems you mention.

 

[costablanca blue]

I'd go more, down to the 60-70 range. (actually, I did, but I recommend the same for you )

If I find a calcium problem on a pool surface I usually decrease TA to just below 50ppm to clear the build up of calcium, then increase TA again once it´s disappeared.

I´m not disbelieving you people, and I understand that swcg pool chemistry is different, but the 60 figure sounds awfully close to the 50 I´ve always used to clear calcium. I always understood that if you leave TA below 50 that eventually you´d lose the grouting between the tiles.

I guess you are recommending 60 though and not 50 but Í´ll have to do my calculations correctly to make sure I don´t overdo the acid :|

You have to keep the other parameters in mind ... specifically the CSI. So if you maintain a lower TA, you may need to increase the CH some or just keep the pH a little higher so the CSI does not get too negative which could eventually cause the grout problems you mention.

understood thanks jblizzle. just noticed your tag - very sad about those poor firemen in your part of the world. those wild fires sounded horrendous.

 

[jblizzle]

You know, I had not even realized there were fires going on when I heard about the firemen ... still have not really heard what happened. I guess I do not pay enough attention to the news.

 

[Jeagolf]

A SWG inherently drives the pH up due to conditions within the cell. By lowering the TA, this should help to stabilize the pH so it will not rise as quickly.

One could easily make the same argument for pools with spillovers or water features that are run a lot.

Am I reading this correct and you are saying that my water feature affects my TA and PH in a negative way? I have my water features on all the time and I am fighting PH and TA levels a bunch.

 

[ping]

Water features that aerate the water will make the pH rise. By keeping the TA lower, 60-80 range, it will help to keep the pH from rising as fast.