CSI level for a vinyl pool

[John85]

Hello,
Pool inheritor/owner of 6-7 years here. I have never worried much about CSI in my pool since it's vinyl but I do have an SWG. Is a below -.6 CSI likely to cause problems in my pool? It says no problem for vinyl unless a CSI of > .6 .

My most recent battery is:

FC 4 CC .5 (need to vacuum)
pH 7.4
TA 60
CH 80
CYA 60
Salt 3400

 

[mknauss]

CSI is no factor, on the low side, for a vinyl pool. You can just turn it off in Poolmath.

 

[John85]

Thanks, mknauss, I didn't suppose so but thought I ought to check with someone who knows.

 

[mgtfp]

The SWG's upper limit recommendation of CSI 0, to avoid scaling in the cell, overrides the general upper limit recommendation for vinyl.

Keep CSI negative is what applies in your case. And pH in the sevens, of course.

I don't see a heater in your signature. Is that correct?

 

[John85]

The SWG's upper limit recommendation of CSI 0, to avoid scaling in the cell, overrides the general upper limit recommendation for vinyl.

Keep CSI negative is what applies in your case. And pH in the sevens, of course.

I don't see a heater in your signature. Is that correct?

Yes. There's an old one on our EQ pad that was disconnected when we moved in.

 

[JoyfulNoise]

Given where you live, you can probably raise your TA a bit (maybe up to 80ppm) as long as it doesn’t cause your pH to rise up. Keeping your pH in the 7.6-7.8 range will also help a lot too. Having highly corrosive water (in terms of CSI) can lead to water that is more apt to cause metal corrosion. If you have any metal hardware in contact with the pool water, like hand rails, etc, then very low CSI water can correlate with water that is also corrosive to metals. If your pool has not contact with metal objects, then it’s not as much of a big deal.

Still, nearly balanced water is always better than just letting the water balance drift.

 

[John85]

@JoyfulNoise and @mgtfp Thanks both of you! A TA raise is in the cards already (and pH to 7.7).

Do either of you have input on my question here? Dolphin Nautilus cord shroud pulled out, help fix

 

[JoyfulNoise]

@JoyfulNoise and @mgtfp Thanks both of you! A TA raise is in the cards already (and pH to 7.7).

Do either of you have input on my question here? Dolphin Nautilus cord shroud pulled out, help fix

Sorry. I gave up on robots long ago. They’re junk and not worth the money spent on them. But, looking at the pictures, I’d say the swivel cord is shot and you need a new one. Could the broken one be “repaired” … probably. But, with all things Dolphin, repairs never last and you’re stuck just replacing expensive components to keep them running. Outside of warranty repairs, it’s not economical. That’s why I went back to using a suction cleaner. The economics of repairing them and keeping them dunking are A LOT better.

 

[xDom]

CSI is no factor, on the low side, for a vinyl pool. You can just turn it off in Poolmath.

What about for a fibreglass pool?
I’m reading that a negative LSI is corrosive on the gel coat?

I’ve been scouring through posts ( Also external sites) for a while, I’m getting different opinions

 

[mknauss]

A low level CH is needed to prevent stains on fiberglass. Most manufacturers state a higher level. No science is presented justifying a higher CH.