Chemistry questions...

AveMaria472

Gold Supporter
Jun 9, 2018
163
Walton, KY
We just opened our pool on Saturday. I think we waited about a week too long and the water was just a hint of green. I added some LQ to 10 FC, threw in the robot, and brushed the sides and within an hour or two all the green was gone. Been running the pump on low and 36 Hrs later the water is still a tiny bit cloudy but steadily improving. The sand filter takes a while. :sneaky:

Here were my numbers this morning:
FC 3.5
CC 0.5
CYA maybe 10 (I filled the tube and could still easily see the dot, though this test has troubled me in the past and I only have enough R-0013 for maybe one more test, I will have more tomorrow)
PH 7.3
TA 50
water temp 55 degrees

My thoughts...
I bought stabilizer but haven't added it yet because I want to make sure my CYA is actually that low first. I thought the FC would burn off very quickly from the sun with the low CYA but it didn't do that so now I'm doubting it is really that low. I did let the water come to room temp before testing. I believe the CYA was at 45 when we closed the pool in the late fall.

I need to raise my PH a little before I start a proper SLAM (if the water doesn't turn crystal clear like it should be. Also, we just installed our heater last year. Should I shoot for a PH of 7.7 for optimal heater health?

Last year I didn't mess with the TA at all and it was low all year, which members here said would be fine to do. Should I adjust the TA to at least 60, or maybe 70?

Given that the PH and TA are both a little low, what is the combination of additions I should make to accomplish both?

Thanks in advance!
Alyssa
 
Last edited:

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
37,112
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Get 20 ppm worth of CYA dissolving using the sock method.
Raise your FC to SLAM level. See FC/CYA Chart based on 30 ppm CYA for now.
Leave pH and TA alone.
Test your FC every couple hours and raise it back to SLAM level. Brush brush brush.
 
  • Like
Reactions: AveMaria472

AveMaria472

Gold Supporter
Jun 9, 2018
163
Walton, KY
@mknauss thank you! To calculate the amount of CYA I need, should I enter 0 in the pool math with 20 as the target? The container I bought says 24 oz per 5,000 gal equals 35ppm. It is a 1.75lb container.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
37,112
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Correct. You need 3 lbs in your pool volume.
 

AveMaria472

Gold Supporter
Jun 9, 2018
163
Walton, KY
Ok, in pool math I entered 0 as current CYA and 20 as target and it says 3lbs 3oz dry stabilizer. I bought two containers which is 3 lbs 8 oz so I will just retain a little in one container. Just added a gallon of 12.5% LQ per pool math to reach target SLAM FC of 12. Water temp already up to 62! Straight sun all day today. Not a cloud in the sky!
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
37,112
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Just add both containers. Nothing is exact in pool water chemistry!!

Use the sock method - not what they say on the containers on how to add to the pool.
 

Enjoying this content?

Support TFP with a donation.

Give Support

AveMaria472

Gold Supporter
Jun 9, 2018
163
Walton, KY
I checked the pool at 8pm after sundown... Nearly all the stabilizer was dissolved. Yay! Hanging the sock in front of the return allowed it to be jerked around quite a bit with the pump on high! The last numbers are:
FC 12 (SLAM target)
CC 0
This means the FC didn’t drop at all from 5pm to 8pm.
I’ll let you know what the numbers are in the morning and how the water is looking.
The kids hope to be swimming by this weekend!
D6C211E3-5CBC-4DC4-A711-DF85583A5B25.jpeg
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
37,112
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Once the CYA is dissolved, let them swim! It is safe to swim in the pool with FC at or below SLAM level.

As long as you can see the bottom of the pool.
 
  • Like
Reactions: AveMaria472

AveMaria472

Gold Supporter
Jun 9, 2018
163
Walton, KY
Well with the water temp below 70, I'd want to turn the heater on before having them swim! And for that I'd want to make sure my PH is in check, which means my FC needs to be below 10 to get an accurate reading on that. Hopefully the PH will checkout ok and I won't need to mess around with it much.
With a PH of 7.3 and a TA of 50 (earlier this morning before the CYA addition and the mini-SLAM in progress) would you recommend I adjust those before calling the water "balanced" and turning the heater on?
Thank you so much for all your help, @mknauss . I haven't been doing the TFP method long enough to always know which is more important to attack first or at all.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
37,112
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
As long as the pH is in the 7's, no need to adjust it. TA of 50 is fine.
 
  • Like
Reactions: AveMaria472

AveMaria472

Gold Supporter
Jun 9, 2018
163
Walton, KY
Drum roll please... it passed!
FC 11.5 (.5 loss)
CC .5 (ever so slight tint/coloration)

Hubby is firing up the heater this morning as this afternoon's forecast is a sunny 77 degrees!
I can't retest the PH until the FC comes down a little more but given that it was in the 7's yesterday, I think we're good.
I'll post another pic of the water clarity once the sun hits the pool.
Thanks again @mknauss . Your contributions to TFP are invaluable!
 
  • Like
Reactions: mknauss

AveMaria472

Gold Supporter
Jun 9, 2018
163
Walton, KY
This morning's numbers...
FC 8.5
CC 0
PH 7.2
water 75 degrees

I was surprised the FC was still that high this morning after about 5 hours of the kids swimming yesterday.

This water is still not quite the crystal clear I know it should be, but as I said before, the sand filter takes time to clear that up. The pump has been running 24/7 since we opened it and I'll leave it that way til it's clear.

We may turn the heater back on for the kids as this afternoon's high is 80 degrees. Do you still think I should leave PH alone @mknauss? I just don't want to risk damage to the heater. We left the bypass open overnight after we turned off the heater so there is water running through it. At what PH level should I be concerned and taking action? Thank you!
 

Enjoying this content?

Support TFP with a donation.

Give Support