Water chemistry - need help!

[Isasate]

to make sure that PB got all the algae.

I'm 100% sure he didn't. So if I'm understanding this correctly, after I get TA & pH & FC in order, I should do a couple of OCLT, correct?

Add 1 pound more of soda ash.

Added. TA is 30 now. Progress!

FC - 4.2 (turned super chlorine mode on again after it reached 3.6 a few hours ago)
CC- 0
pH - bellow 7, but this time it only took 6 drops to get to 7.2

Brush the CYA around on the floor until it dissolves.

Brush the cya around. It should not be a big deal with your fiberglass.

Done. CYA almost 100% dissolved. Added 42oz for the recommended target of 40. Will test tomorrow or in two days.

 

[mknauss]

Test TA and pH tomorrow. If TA still at 30, add 1# more soda ash.

 

[MITBeta]

I'm 100% sure he didn't. So if I'm understanding this correctly, after I get TA & pH & FC in order, I should do a couple of OCLT, correct?

Yes.

 

[Isasate]

Happy Friday! New tests:

3/18/2022

FC - 6 (with 10ml) - 6.6 (with 25ml)
CC - 0
TA - 30
pH - <7, 4 drops to 7.2, 5 for 7.4
CH - 90
CYA - 60 - 70

Turned super chlorine mode OFF. Not sure if I need to adjust the %, currently at 80%. Pump is running at 1750 - 12 hours. I'm considering lowering it to 8hrs. I'm not familiar with with so all I have is guesses.

Not sure what went wrong with the CYA. I only added 42oz (2lbs 10oz), to get something close to 40, but instead I got 60 - 70!

I will add another pound of soda ash.

I have to say after this test I vacuumed the pool and added a bit more water. It looking amazing, even with the chemistry being as wonky as it is right now.

 

[mknauss]

Test the CYA after a few days. Either there was a lot more in the water before adding the granular, or the pool volume is much less. See if the test results change after a few days.

Good call on the soda ash. After this add, I suspect you can wait awhile.

When you are ready, do the Overnight Chlorine Loss Test. Target a 10 ppm FC in the evening, and see what results you get the next morning.

Good job.

 

[Isasate]

Either there was a lot more in the water before adding the granular, or the pool volume is much less. See if the test results change after a few days.

All my tests came back with 0 CYA. This has been the only one when the sample turned cloudy.

I want to rule out pool volume being less, since the TA adjustments are coming in nicely. I asked the pool manufactured and my PB and they both told me the pool holds 7,800 gallons.

The only logical explanation is that I messed up my measurements and added more granular. I checked multiple times but it is the only reasoning I can find here.

In any case, I will follow your suggestion (as always ) and test in a few days. I will also do the Overnight Chlorine Loss Test Does it matter that the pH and TA are not fully there yet?

 

[mknauss]

Does it matter that the pH and TA are not fully there yet?

No. They have no effect on the FC tests.

 

[Isasate]

I noticed 3 more dark "stuff" in the shell.



As the previous ones, they won't come off with brushing or scratching. I did see 2 screws (yes...) in the skimmer basket. They were black and now they rusted. Could they be the culprit?

I mentioned to my PB and he told me he is coming next week. I'm scared of what he might do now...

 

[mknauss]

Could they be the culprit?

Have you tried the vitamin c test I suggested?

 

[Isasate]

Have you tried the vitamin c test I suggested?

No, not yet. I might want to do it before he shows up. Any suggestions of what exactly I should buy? Thanks

 

[mknauss]

Vitamin C tablets. Cheap ones. Put a handful in a thin sock. Crush them up a bit. Hold it against the stain for a few minutes.

 

[Isasate]

Vitamin C tablets. Cheap ones. Put a handful in a thin sock. Crush them up a bit. Hold it against the stain for a few minutes.

Got it. Will buy them as soon as I can and test it.

I got new test results today. To say I'm confused is an understatement.

03/19/2022
FC - 12!!
CC - 0
pH - 8!!
TA - 60

What in the world is going on? I only added 16oz (1lb) of soda ash yesterday. SWG is at 80%, no super chlorine mode. I turned it off completely.

I don't want to freak out, but I don't understand what's going on. Temperatures are higher these last couple of days, full sun in the pool. Maybe that is affecting the chemicals? I'm lost.

 

[Bperry]

Got it. Will buy them as soon as I can and test it.

I got new test results today. To say I'm confused is an understatement.

03/19/2022
FC - 12!!
CC - 0
pH - 8!!
TA - 60

What in the world is going on? I only added 16oz (1lb) of soda ash yesterday. SWG is at 80%, no super chlorine mode. I turned it off completely.

I don't want to freak out, but I don't understand what's going on. Temperatures are higher these last couple of days, full sun in the pool. Maybe that is affecting the chemicals? I'm lost.

You’ll need to adjust the SWG periodically as you watch the FC. No big deal. Just turn it up if you find the FC dropping below where you want it and do the opposite if it climbs too high. No need to shut it off, just drop the % a bit and check again the next day.

 

[Isasate]

You’ll need to adjust the SWG periodically as you watch the FC. No big deal. Just turn it up if you find the FC dripping below where you want it and do the opposite if it climbs too high. No need to shut it off, just drop the % a bit and check again the next day.

Thank you

 

[mknauss]

Soda ash is a big hammer when adjusting TA and pH. Also, a FC of 10 ppm or higher skews the pH reading to the high side.

Wait s day or two and check pH again when the FC is under 10.

 

[ajw22]

Great! You got your water chemistry back to a reasonable level.

Now let everything settle down and just test it daily. Let's see how your FC drops before you do anything more.

 

[Isasate]

Phew! I feel better after reading your comments. Thank you! I will continue monitoring, and I'll see if I can do the overnight chlorine lost test as well.

 

[Isasate]

First OCLT pass! Tested 12.5 at night, just minutes before pump shut off. This morning, pump on, tested 12.5 as well.

However, I think I might want to do another one with 25ml instead of 10ml. Those that matter?

I think I'm going to keep the SWG off for today, while I read about how to adjust it. It would be sweet not having to run the pump 12hrs as my PB instructed us. SWG at 80% & pump 1750rpm 12hrs is too high.

Any suggestions about how should I approach this? I read the PoolMath web version has an option for SWG, so I'm going to start there.

 

[ajw22]

You passed the Overnight Chlorine Loss Test. Move on.

What RPM are you running your pump?

 

[mknauss]

Start with creating 3ppm FC per day. At 80% swcg setting, 4 hours run time will get you that. If that is sufficient to skim the pool, try that. Test FC and adjust the % setting to maintain your target Fc.