Trying to prevent scaling - how does my CSI look?

[rdbrya1]

When I plug in all my numbers, my CSI shows -.3

Here are my numbers:

FC: 10
Alk: 90
PH: 7.9
CYA: 90
Salt: 3200
CH: 125

I read the SWG Recommended Chemistry numerous times and my question is...it says once PH reaches 7.8 to lower it back down to 7.5. However, if I bring it down and keep it around 7.5-7.6 that makes my CSI become -.61. Should I add acid now or leave everything as is and keep it here since my CSI is at a good number of -.3 ?

We have hard well water as it is so I am just really wanting to keep chemistry perfect so that my cell stays really clean with no scaling.

Thanks everyone!!

 

[Texas Splash]

A low CH/CSI is not an issue with your vinyl pool since there is no plaster to be concerned with. Scaling should not be an issue at that CSI. You should still adjust pH to remain under 7.8, and even the TA could come down slightly to the 60-80 range which may help prevent frequent pH increases over the season. Pool School - Recommended Levels

Hope that helps.

PS - More than anything I would be concerned about that elevated CYA of 90. I know you have a SWG and require an elevated CYA, but did you add stabilizer on purpose to make it that high, or are you also using chlorine tabs/pucks, or perhaps bags of shock at times?

 

[rdbrya1]

Thanks for the reply!! I very recently converted to SWG (maybe a month ago), so unfortunately the CYA is still high due to using tablets over the last few years. I keep draining and refilling a little at a time to get it down lower so hopefully I will get there soon! (It was over 200 when I had to drain the pool nearly 1/2 before installing the SWG :-( )

So it sounds like other than that I am doing pretty good!? (guess that is more of a question, ha!). I will go ahead and lower the PH today down to 7.5.

So even with the CSI fluctuating between -.7 and -.3 over time I should be good with scale building up on my cell? I keep reading that as long as CSI stays between -.3 and 0 there should be little to no scale build up. So even a lower CSI of -.6 should keep the cell clean? I am only worried about buildup on the salt cell, not the liner or in the pool (if that makes a difference).

Thanks again!!

 

[Texas Splash]

That makes sense. Yes, your odds are much better to avoid scaling with the CSI in the negative. Even easier to do since you don't have plaster to worry about. Enjoy!

By the way ... thanks for being a TFP Supporter!

 

[rdbrya1]

Awesome!! Thank you again!! I'm glad to be a supporter!

 

[pooldv]

Yes, you are doing fine. The -0.3 to 0 recommendation is for plaster pools that also need to be concerned about etching the plaster. With a vinyl pool there is no concern there. -0.7 to -0.3 will work great.

+1 to thanks for supporting TFP!