Chemistry After Water Replacement

dfiletti

LifeTime Supporter
Jun 12, 2008
76
Thornton, PA
Folks-

I replaced ~ 14K gallons of my water below is my old, (prior to refill) new, and fill water chemistry.

Old Water (before the replace)

Date: 8/14
Temp: 85F
FC: 1
CC: .5
TC: 1.5
T/A: 45
C/H: 650
CYA: 50
Salt: 3,200ppm
pH: 8.0
Filter pressure: 22 PSI
SWG Setting: 20%
Pump Run Time: 8 Hrs./ day
Heat Pump: Standby

Action taken after readings gathered:

Replaced 50% of the water.

##########################
Fill Water: (two hoses)
Date: 8/15
Temp: ~60F
FC: .5
CC: .25
TC: .75
T/A: 65
C/H: 100
CYA: 0
Salt: N/A
pH: 8.0

Action take:
Added 2 gallons of MA
Added 160 lbs salt (still need to add more)
Added 3 gallons bleach.
##########################

New water:

Date: 8/17
Temp: 72F
FC: 1.5
CC: .5
TC: 2
T/A: 20
C/H: 410
CYA: 25
Salt: 2,400ppm
pH: 7.0
Filter pressure: 22 PSI
SWG Setting: 0%
Pump Run Time:24/7
Heat Pump: Standby
Additional information: it rained ~3" last night, had to drain some water this am before testing!!

So, I see that my salt, CYA, TA and pH are too low.

My action plan is as follows:

Add another 140 lbs salt -then,turn on SWG to 50% (FC Target: 3.0)
Add 13 lbs of CYA to get CYA Levels to 80
Add 21 lbs of baking soda to bring TA up to 70

I figure that the baking soda, and SWG will bring the pH up so I'll wait to see if adding that is enough before correcting that.

Would you folks do any else/ differently?

Thanks!

Dan
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
22,069
San Dimas, CA (LA County)
I'd get some more bleach in there ASAP, so there's something keeping things clean until the SWG can catch up. And I would aim low on the CYA. It's easier to add more later than it is to remove excess.
 

duraleigh

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In The Industry
Apr 1, 2007
32,859
Sebring, Florida
I would probably target a CYA of around 60 at first and let things settle in. Then, I would retest and adjust if necessary or perhaps just leave it alone if your season is closing down.

You're smart to leave pH alone. It'll come up

Ditto what Richard says about the chlorine.
 

dfiletti

LifeTime Supporter
Jun 12, 2008
76
Thornton, PA
So, in my haste I bought "Washing Soda" 4/ 5lb boxes. I added one, 5lb box and things clouded up really badly. Oops.

Edit: it actually A&H "Super Washing Soda"

So I stopped, and did not add the other 3.

How badly did I mess this up?

Will/ should the filter clean this up?

Feeling a bit stupid...
 

dfiletti

LifeTime Supporter
Jun 12, 2008
76
Thornton, PA
According to the MSDS, A&H Super Washing Soda is made up of 85% Sodium carbonate, 15% water. I also read where it reacts with acid to produce CO2 gas, could it be reacting with my low pH, or the CYA I added?

Just guessing.

Dan
 

dfiletti

LifeTime Supporter
Jun 12, 2008
76
Thornton, PA
OK, so the pool is clearing up now. Feeling relieved. So from what I can gather, I managed to take steps that are aimed at increasing pH, not so much TA. -Although, I get that they're related.

I'm thinking I'm going to keep my remaining Washing Soda, not use it just now, it makes the water scary-cloudy, and go out and buy 15 lbs of Baking Soda. Should I expect the Baking Soda to cloud up the water as much?

Thanks,

Dan