Full drain, Adding Borates vs. CSI danger-zone

capn7

Silver Supporter
Mar 6, 2013
21
Phoenix, AZ
#1
Greetings,

Did a full drain a month ago (CH was ~1100 - Phoenix :( ) and would like to add borates back in as I had in the past. My pH tends to climb quickly, so the borates were a blessing!

One thing I'm struggling with is the CSI when I play around with the calculator... After plugging in assumed borates level, I seem to be uncomfortably towards the edge of the CSI range.

NOW: 74°
FC 3.6 (on SWG); CC 0
pH 7.6
TA 100
CH 260 (it will drift upward somewhat rapidly during the Phoenix evaporative summer)
Salt - 4k
CYA 70
Borates - somewhere just above 0 (residual from a couple hundred gallons of old water leftover)

I've read here to drop the TA to 60-80 *first* before adding borates. But when I go to the calc and plug in assumed values of TA=70 and Borates=45 (all other numbers as shown above), the CSI is -0.56, "potential to become corrosive to plaster."

Should I be concerned with this? Babysit it and just be extra cautious until my CH & water temp comes up (bringing the CSI back from the deep end - hehe)?

I appreciate any advice!


-Aaron
 

pooldv

Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
24,993
DFW, TX
#2
Do all of above except let your pH hang out at 7.8, lower it to 7.6 when it gets to 8.0 and you'll be good.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,197
Tucson, AZ
#3
Agreed.

I just did a full water replacement too. My CH is lower than yours, just compensate by keeping the pH a little higher ... since we both know how quickly the CH will go up ;)
 

dooger54

Well-known member
Apr 21, 2017
81
Tucson AZ
#5
Agreed.

I just did a full water replacement too. My CH is lower than yours, just compensate by keeping the pH a little higher ... since we both know how quickly the CH will go up ;)
Jblizzle-

saw where you are in Tucson also. I just drained and refilled my pool because CH got so high. Are you saying that keeping the pH a little higher helps keep CH down here in Tucson? New user here.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,197
Tucson, AZ
#6
No. The CH will rise constantly. The higher pH will keep the CSI in acceptable range while the CH is low. As the CH rises, you need to start lowering the pH. Check out PoolMath.