How soon should I retest?

[thunderkyss]

Getting ready to go test again. If the TA is still not at 70, which I feel it won't be, I'll be adding another gallon of muriatic acid. I suspect it will be in the 90 range.

The CSI at last test, was 0.16, PH was 7.6

I'm sure the 7.6 will have gone up by now..... adding more muriatic acid and lowering the Ph will drop the CSI.

Any objections, please speak up.

 

[thunderkyss]

Newest numbers.

TA: 80 I didn't add any muriatic acid
Ph: 7.0

retested my CH: 325 using the less accurate (10ml sample) method. It splits the difference between my previous 270 & the pool stores 400.

Putting these numbers in the pool calculator, it suggests I add 99 oz. of baking soda. 122 oz of borax. and tells me my CSI is -0.51

I'm going to leave it alone for tonight, leave my pump running on high speed through the night. I'll test it in the morning to see what's what.

 

[thunderkyss]

Found this in another thread.

OK fellow mods, don't shoot me for saying this :bowdown: but I say, try it out Trichlor pucks are acidic, which is why it's keeping your TA in check.

If this is true, & I have no reason to believe it isn't, then I understand why my pool builder was confounded with the sudden rise in TA.

He left me about two weeks worth of Tri-Chlor. I used them till they were gone then started using liquid bleach.

That's when my TA shot up.

 

[JasonLion]

That makes some sense. Trichlor is acidic, so it would have been helping to keep both the PH and TA in check. Still trichlor isn't that acidic, nothing to compare to a gallon of muriatic acid, so that doesn't completely account for it.

Using trichlor with a fresh plaster startup is generally a good idea until you have used enough to get the CYA level up to around 30 to 50.