Pentair Ichlor getting calcium buildup every time I use heater

[malu95]

Hi all,
I have had my pool for 4 years and recently shortly after I use the heat pump, the swg salt button turns solid red. When I open it I can see calcium buildup and after cleaning it everything starts working properly again. If I don’t use the heater, it remains that way but I noticed that in the last 3 weeks every time I use the heater, the calcium buildup shows up within days.

Current chemistry measure by Taylor 100-pro:

FC: 3.5
CC: 0.5
Cya: 60
CH: 350
Alkalinity: 100
PH: 7.2 (I was reducing alkalinity from 200 level and now aerating to bring ph higher to ideal range)

Thank you!

 

[mknauss]

The higher temperature raises the CSI at the cell. Very high TA. Get that down to 70 ppm or so and it should stop.

 

[ajw22]

If the scale on the SWG does not stop with a TA of 50-70 ppm consider adding 50ppm of borates to the pool. It will stabilize the pH in the cell.

Borates in pool - Further Reading

www.troublefreepool.com

 

[malu95]

The higher temperature raises the CSI at the cell. Very high TA. Get that down to 70 ppm or so and it should stop.

Does that 70 target exclude the adjustment for CYA? My CYA is at 70 so adjusted alkalinity is much lower than the 100. From what I understand the adjusted alkalinity is a consideration when calculating CSI but not the Taylor kit alkalinity test and target is that correct? Thanks again!

 

[mknauss]

Adjusted alkalinity is a pool store scam.
Use TA.

 

[malu95]

The higher temperature raises the CSI at the cell. Very high TA. Get that down to 70 ppm or so and it should stop.

My current CSI is negative -0.33 per pool math app: ph 7.3 (trying to raise it as I lowered alkalinity), alkalinity 100, calcium hardness 350, cya 70, water temp 86. If I lower alkalinity to 70, that takes my CSI to -0.54. Is that not an issue?

 

[mknauss]

What pool type do you have?

Otherwise your cell is failing as it is not switching polarities to shed the scale.

 

[malu95]

What pool type do you have?

Otherwise your cell is failing as it is not switching polarities to shed the scale.

We have a fiberglass pool. That’s a good point, maybe it is the cell itself

 

[mknauss]

CSI is of no concern for your pool shell. If you have water line tile with cement based grout, then you need to be mindful of it.

 

[malu95]

CSI is of no concern for your pool shell. If you have water line tile with cement based grout, then you need to be mindful of it.

Nope it’s all fiberglass so that’s good to know. And what about the impact of CSI on other pool equipment like the heat pump? It is a pentair ultratemp 120 c/h heat pump.

 

[ajw22]

Nope it’s all fiberglass so that’s good to know. And what about the impact of CSI on other pool equipment like the heat pump? It is a pentair ultratemp 120 c/h heat pump.

None