CSI help


Silver Supporter
In The Industry
Aug 15, 2017
Spring Valley, NY
Pool in question ISN'T pool in signature:

IG 28000 vinyl, SWCG RJ-60PLUS, NG, AUTO COVER, Polaris Robot P955,

2019 Mid November close not by me, was done correctly and covered with mesh looplock. I had it up to slam level with LC right before close. fast forward....opening was yesterday

I removed mesh winter cover without getting any foliage into water, got piping de-winterized and pump running all is good there. Vacuumed with inline leaf catcher, Let pump run half hour before taking water sample. SWCG is inline but not powered until water checks out. Here are the numbers from unadulterated overwintered water.

TEMP AS TESTED-70 deg (water sample at room temp)
CSI- -87

Slammed last evening and this morning had lost of .5ppm FC (1/2ppm) and CC was down to .5 too.
So while playing with Poolmath the only ingredient that will make a good dent on the CSI is upping the CH with sodium chloride. Poolmath has it if I bring the CH up to 300 it'll cause a CSI value of the -.4 to -.5 Am I safe at that using THIS calcium chloride as per PM I would need 39 lbs. Do I mix a few pound at a time in a bucket and dispense into the deep end or something else. What would be my parameters either side of "0" so the SWCG stays clean. Last year the cell ran 4 months with slightly negative CSI and the cell doesn't look a day old. I want to keep things running this way. Thanks in advance,

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Allen, for the vinyl pool you are helping, I don't think CH is really needed, and neither is worrying about a low CSI for that matter. A high CSI (scale) sure, but there is no plaster for erosion, so I wouldn't worry about it. If you feel like bringing the CSI up a little just for your own peace of mind, I would bring the pH up to about 7.7 to 7.8. That will balance it out quickly. I think you have a handle on the rest. :goodjob: