How concerned with Saturation Index should I be?

[HamSammich]

I just completed my weekly level check (K2006) and came up with the following results:

FC 7
PH 7.4
TA 50
CH 180
CYA 80
Salt 3500 ppm

Plugging my numbers into the PoolMatch calculator I come up with a SI -1.12. Reading the Taylor manual, this is bad. Now that the water temperatures have dropped that number has gotten out of hand. Should I be concerned with the SI?

Thanks!

 

[zea3]

Keep in mind they are looking at the water being corrosive to plaster pool finishes. You did not report a salt level. Are you using your SWG? When you plug your numbers into Poolmath be sure you have it set up for a vinyl pool.

 

[HamSammich]

Ahh yes. Forgot about that. Salt added.

 

[eqbob]

You should probably add calcium to get that number closer to recommended levels.
You could also add baking soda to raise your TA if that's a lower level than you usually maintain.
Those changes would make the water more balanced.

 

[JamesW]

No need to add calcium to a vinyl liner pool. The TA is fine if your ph stays good. If the ph drops below 7.4, I would raise the TA to about 60 ppm, otherwise I would leave it alone.

 

[eqbob]

My bad. I read a follow-up post that mentioned plaster and missed the listing of vinyl in the signature. Definitely wrong advice.