Am I doing this right?

[LS1M]

OK so yesterday we actually swam in the pool! Yay! After 18 days of shocking and a few days to let the FC settle down, and it was actually warm enough - ahhh, felt good.

So, I want to get everything just right. I measured TA at 70, so I added baking soda to bring it up to 90. Today, it was at 90. OK so far. My pH was at 7.2, so I added Borax to bring it up to 7.5. Afterwards, it was right at 7.5, so far so good, right?

Now I went to adjust my CYA. It was at 40 or so, and I added some CYA (sock through the skimmer) and it took all night & day for it to dissolve completely. Pump ran all night, and I just did a full chemistry check:

FC: 5+ (just a bit more yellow than 5)
pH: 6.8 (?!)
TA: 90
CYA: 70
Salt: 2800ppm

So it looks like I hit all of my targets, but for some reason the pH is down again. Is that the normal reaction when adding CYA? I assume so, since it's acidic.

I just added more Borax to bring the pH back up. Hopefully I'm doing all of this right...

Thanks. Just want a sanity check here... I'm still pretty new at this. Last year, I just ran the chlorine generator 4 hours a day and took pool samples to the local shop, did whatever they said...

-Mark

 

[duraleigh]

Any pH in the 7's is okay. I think I would just leave it alone and let it come up (which the SWG will cause it to do.) Everything else is fine.

 

[Richard320]

Pool Calculator tells me that pH will go down when adding CYA. It's near the bottom: effects of adding chemicals.

Your CYA should be high enough. Don't add any more.

The rest of it is easy: keep pH in range, and don't let FC drop below minimum for the CYA level. With a SWG, you'll likely be lowering pH more than raising it. That's it. TA will adjust itself if you keep the pH right all the time. Don't obsess over some target numbers, either. You'll end up on the same roller coaster the pool store had you on.