How to check for safe pH when above 10 FC following SLAM

[TexasDogs]

Coming down off a SLAM and things are looking promising. Filter is chugging away and clarity is coming back. The heat is also back so I'm looking to make a splash soon! How can I make sure the pH is at an ok level for swimming when my FC is still coming down?

I brought pH down to 7.1 prior to SLAM, so can I just assume it's good enough for now while FC is too high to get a good pH reading?

I have 80ppm CYA (waaaay better than it was last week, but still a little high), so my SLAM level was 31, and it's taking a surprisingly long time to come down. Currently down to 16, but the sun is out in full force so maybe it'll be down below 10 by tonight. So it may not matter this time, but for future reference, I'd still like to know.

 

[BassPlayingDude]

Digital pH meter

 

[Donldson]

Not really any unsafe pH level that you'll find in pool water. I wouldn't worry about it unless swimmers noticed their eyes were stinging, but even then it's not unsafe just uncomfortable.

 

[mknauss]

Coming down off a SLAM and things are looking promising. Filter is chugging away and clarity is coming back.

FYI- first criteria to end SLAM Process is crystal clear water.

 

[TexasDogs]

FYI- first criteria to end SLAM Process is crystal clear water.

Good point. I was rash, and I should bump back up to SLAM, but then I guess that makes my question incredibly relevant. If I go bump back up and maintain SLAM levels, and I get clarity, and then drift down to normal levels, how do I know when pH is safe for swimming?

 

[mknauss]

See response above from Donldson. The pH in a pool, unless you purposely add many gallons of acid, will always be 'safe' to swim in. Only pH below 7 is 'uncomfortable', typically irritating eyes and may dry skin/hair.

 

[TexasDogs]

See response above from Donldson. The pH in a pool, unless you purposely add many gallons of acid, will always be 'safe' to swim in. Only pH below 7 is 'uncomfortable', typically irritating eyes and may dry skin/hair.

Interesting. So aside from comfort, is the only reason to stop pH from rising to keep the CSI in check?

 

[zea3]

There is a longer, more technical explation, but essentially pH also effects some chemical processes. Very high pH (over 8.0) can render chlorine less effective. Low pH can pull calcium from plaster walls, not safe for your plaster but it won't hurt you. High pH combined with high calcium can form calcium scale, which is only unsafe for you as it makes the surface rough and can cause abrasions when you rub against it while swimming.
Main reasons to keep pH in line are comfort and aesthetics.

 

[Donldson]

Overly basic water can be just as uncomfortable as overly acidic.

Brief pH swings in to the 8's or 6's are not a major concern, but long-term will cause problems. That's why it's not a big deal when you're in the SLAM Process to not monitor pH, but treating it as unimportant will lead to problems sooner or later. Don't forget too that just because something is safe for human skin doesn't mean it's good for it, nor good for the pool finish. I sometimes pick up wet trichlor and it's generally fine. Doesn't mean it's a good idea to hold it for a long time or leave it sitting on my liner.

 

[BassPlayingDude]

Or lick it LOL

 

[BassPlayingDude]

Seriously folks, all jesting aside, PLEASE don't lick trichlor tabs!!! It ends in tears...