New test kit - looking for next steps

[lichen]

Last week I received my Taylor K-2006 in the mail. I have a in-ground plaster pool that is roughly 18,000-20,000gal. I have been testing regularly and got the following results:

8/31 pm-
FC - 5.5ppm
CC - 0.5ppm
CYA - 100+ppm
pH - 7.9
CH - 220ppm
TA - 100ppm

9/1 pm - Added 1gal 8.25% bleach

9/4 pm -
FC - 3ppm
CC - 0.5ppm
CYA - 100+ppm
pH - 7.9
CH - 210-220ppm
TA - 100ppm

9/4 pm - Added 121oz 8.25% and 96oz 6%

9/5 am -
FC - 8ppm
CC - 0.2 ppm
pH - 8

9/6 am -
FC - 5.5ppm
CC - 0ppm

I was just looking for some thoughts and input on what needs to be tweaked. My water is currently pretty clear and overall I'm happy with it. The CYA is high, but I think I should probably wait until winter to replace that water since we're currently in the middle of water restrictions. Given the CYA it looks like I should be maintaining a FC around 12, and currently I have been keeping it between about 4-9, so I guess I need to work on that. Additionally, it seems like I should lower the pH just a little bit? I know that when you have a high FC that the pH will read high, but does this take into account the CYA? For instance, since my CYA is so high and I need to maintain higher FC levels, is my pH ever going to read correctly? How does the TA and CH look?

A couple of other points of concern: There is orangeish staining on a decent amount of the plaster on the bottom of the pool (I should get a picture of this). It doesn't seem to be mustard algae as it won't brush off. Is this some sort of scaling and is there anything I can do about it?

Secondly: The water always really dries out our skin after swimming for a few hours. Is there anything we can do about that?

Lastly, is there anything I can do, based on that numbers, that should make the overall quality of the water more enjoyable? Thank you for any insight!

 

[Richard320]

Lower the pH. That should help with the skin. The pH test is accurate up to at least 10 FC.

And be scrupulous about maintaining FC. If you get an algae bloom, you'll be buying bleach by the barrel to clear it.

 

[Stuamurr]

Half dilute your cya test to at least get a rough idea of where it is, that will allow you to maintain the right FC level as Richard has already said, TA fine for a plaster pool but you do need to bring pH down to around 7.4 which will help considerably with bather comfort, CH fine also.

FC under recommended levels for your CYA level will still work but the Free Chlorine residual is not as effective, so an algae bloom is a high risk, you can let FC drop to the >10ppm range in order to get a good pH reading, before pumping the FC level back up.

Post a wee pic of your orange problem for some more help on that.

Regards
Stuart