First Spring with a SWCG

I had a Pentair IC40 installed in July of 2014 and it has worked without too many issues. However, now it is spring in southwest Georgia and I have been told by my granddaughter that she and her friends are ready to swim.

I had previously used the BBB method of pool maintenance and I would now like to know what the proper ranges are for pool chemistry now that I have a SWCG system.

As of my last check this morning ....pH 7.4, FC 2.2, ALK 90, CYA 55 and salt 2500. I have a 25000 gallon pool, well water with vinyl liner. The pool at present has some green algae and I just about have all the organic matter cleaned out.

Any help would be most appreciated.

jhk49

Hi JHK,

I have a plaster pool in the desert so my numbers may not be too instructive but here are the ranges I shoot for and my most current test results (I have an IC-40 too) -

Ranges-

FC 3-5
pH 7.5-7.8
TA 60-80
CH 250-350
CYA 70-80

Most Recent Tests -

FC 6.4ppm
CC <0.2ppm
pH 7.6
TA 90ppm
CH 550ppm
CYA 70ppm
Salt 4000ppm
Borates 55ppm

Two things I learned with running the IC40 -

1. Only use the built-in salt level indicator as a sanity check. The Pentair IC's are NOT temperature compensated and so the readings will drift with water temperature. Each unit can be different so note the temperature of the water when you set the salt level and you should get a good idea of the drift. Set your water's salt level using an external test kit (AquaChek strips or Taylor 1766 drops) and then forget it. You only need to check your water's salinity in the event of a major water exchange like a flooding rain storm or a partial drain & refill.

2. SWCG sometimes increase acid demand. Keep an eye on your pH and don't be surprised if you are adding acid more frequently. SWCG's have a tendency to raise the pH of the pool water as a result of the electrochemical chlorine generation process. In my pool, my acid demand falls way off in the winter months (my pool is "open" year round) when my IC40 is not running and, as soon as the it starts running more frequently (without any bather load), my pH drifts up faster and my acid additions increase in frequency. That's been my experience but yours could be different.

Cheers!