Quote Originally Posted by CarlD
Which of those is "Really Orange"? Light Orange or Dark Orange...
Why Carl, I'm surprised you aren't aware of the OIS (Orange Intensity Scale). It goes like this:
  • Not Really Orange aka Light Orange with a Yellow Tinge
  • Almost Really Orange aka Orange with just a flavor of Yellow
  • Really Orange aka Just Orange; Ain't No Yellow Here!
  • My GOSH Are We Swimming In That Orange aka Dark Orange with hints of brown
  • Beyond Orange aka Brown.
. .
But seriously, those colors are meaningful. I think I've also descibed then as being "Brown = Don't Panic, but Get Everybody Out of the Pool" and "Orange = Don't even THINK of adding more chlorine. Meanwhile, they can swim, but only with OLD swimsuits!!" As it happens, I've found kiddie pools at "Brown" several times. We got the kids out, without panicking anyone ("Folks, the chlorine's a little high, and we need to close the pool for an hour or so."), and apparently, with no ill effects.

The fact that those colors EXIST is one of the major reasons I LIKE having the OTO kit in the PS23x series -- the OTO test is quick, easy, meaningful, and almost bombproof.

Most of them, you can operate quite successfully with the following verbal scale:
  • Yellow to Dark Yellow => Ideal
  • Light Yellow => Add chlorine
  • Orange tinted => Swimmable, but too high, unless you are shocking or have high CYA
  • Orange => Old swimsuits only! Ideal for algae cleanup.
  • Brown => Too high for people and vinyl pools.
    (Not dangerous, but it will fade things, and sting eyes. You might get a little chapped where the sun doesn't shine, too.)
    Great for concrete pool cleanup.
Now, you can get meaningfully better results using the DPD-FAS, and tracking things more closely than that. But, using that scale alone, probably 1/2 the pool owners in the US could do better than they are now!

Ben