Large Salt particles clogging up SWCG

[jblizzle]

I don't think you understand the difference between FC, CC, and TC. Read this: ABCs of Water Chemistry

Also, what test kit are you using? Do you have the FAS-DPD chlorine test or just the yellow OTO color matching test?

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The multiplier depends on how much water you used for the sample. 25ml = 10ppm per drop ; or the now recommended 10ml = 25ppm per drop

 

[hyperionguy]

thanks chem geek for the detailed explanation, i never heard it before. I knew the theory behind why SWG pools can get away with slightly lower FC relative to CYA but didn't know the specifics around what goes on within the cell regarding scaling. Cool stuff!

 

[Hound Dog Charley]

Yup, I was definitely mixing those 3 up.

Just retested. chlorine has gone down from morning test cause pool has been open and SWCG has been off due to calcium buildup and need for an acid clean

FC = 3.5
CC = 0

 

[chem geek]

(deleted irrelevant post)

 

[Hound Dog Charley]

So I added a gallon of acid yesterday per the pool calcualtor and my TA didn't even go down. Kept waiting for solution to turn red but it stayed green till the 21st drop... so 210. What gives?

Its not hard to count drops, I redid the test to be sure... so I don't know. This is probably whats causing my scaling... my TA has always been a problem. PH went down to 7.5

I guess I just keep adding acid right?

 

[JohnT]

yes, definitely right.... it could be higher even, its dark yellow

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btw, im about to add a gallon of acid per the pool calculator to lower my TA and PH

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also, I just looked on the tfttest kits site and for the CH test it says multiple by 25, yet on the laminated sheet i got with the kit it says multiply by 10... any idea which one it is? http://tftestkits.net/Test-Kit-Instructions-10.html

With a 10ml sample, you multiply by 25. With a 25ml sample, you multiply by 10.

 

[jblizzle]

Was it 31% acid?

One gallon in your big pool should have lowered the TA by about 12ppm (according to PoolMath) ... so that is close to the accuracy of the test.

You can add acid to lower the pH to about 7.2 and then you have to wait and/or aerate to raise the pH so you can add more acid.

 

[Hound Dog Charley]

Was it 31% acid?
.

yes, 31%