Salt and TA questions

[bstucker]

Hello all, I just have a couple questions.

As I convert to a SWG this next week, I am wondering about how much salt to add. I have tested my water and it shows 1400ppm of salt already. I know this is from using bleach for my chlorine. Will this salt that's already in the pool work just as well as adding the recommended bags of salt?

My next two questions are related to TA in general. First, what all can cause it to rise other than ph-up and other products like that? Next, does aeration alone lower TA, or do you need to use MA+ aeration to lower and control ph at the same time?

I'm basically looking to find a "trouble-free" way to maintain both my ph and TA. I've been looking at the Intelliph or Intellichem to automatically dispense MA to lower them both.

Thank you all.

 

[JasonLion]

Salt is salt, it doesn't matter where it comes from.

TA increases when you add baking soda (also called Alkalinity increaser and various similar names) or soda ash (also called PH Up and various similar names). Baking soda increases TA dramatically, while soda ash mostly raises PH, but will also raise TA a little. Also, any chemical that raises PH will also raise TA just a little tiny bit.

TA goes down when you add acid. Aeration raises the PH without raising TA. All other ways of raising PH also raise the TA a little.

The only reason to use an IntelliPH, or anything similar, is if your fill water is high in TA or you have a really huge amount of aeration (typically a negative edge or huge waterfall). Otherwise it should be possible to arrange things so that both PH and TA are fairly stable.

 

[woodyp]

Salt is, well.......salt! Just add to what you already have up to the recommended level for your SWG. Aeration raises PH. Lowere PH with muriatic acid and at the same time decreasing your TA a bit. See the recommended ranges in pool school.

 

[bstucker]

Is there any way that TA and ph would drift upwards without adding baking soda or soda ash? Or would high values of these in my fill water be the main cause of this?

I'm looking at the intelliph or intellichem because I believe i have several factors that contribute to my rising PH. First, I have 4 waterfalls and 2 fountains in the pool (1 of which is a groto), a second groto in the spa, spillways from the spa to the pool, and spa jets. Next, I'll be adding a SWG this week and I've read that ph will tend to drift up with this. Finally, I know my fill water has high ph,and possibly high TA.

 

[JasonLion]

TA does not tend to go up on it's own. PH, on the other hand, tends to go up because of CO2 outgassing when there is aeration.

It is worth measuring your fill water TA level before investing in anything like the IntelliPH. From the sound of things you may indeed want one, but best to be sure.