Kudos on your foreclosure -- been there, done that, bought the t-shirt

what a beautiful pool!
I might have some insights on staining, but first have a few maintenance questions and suggestions.
Are you keeping your cya at 80 because you're using a swg (salt water generator to chlorinate)?
Or are you using trichlor tablets to maintain chlorine, which adds a lot of cya?
See
pool-school/chlorine_cya_chart_shock
80 cya is getting on the high side, and cya stabilizes chlorine but also once high reduces its capability to sanitize...which is why you need to maintain daily higher doses of chlorine when you have higher cya...see the cya/chlorine chart in pool school. If you don't maintain same, ultimately you can end up fighting algae outbreaks, which can start as cloudy appearance to water.
If you're not already, now that you're up and running you may wish to use liquid chlorine (household bleach or the 10 and 12.5% sold in stores and pool places) to maintain your water to avoid having to drain when cya gets to 100.
The only way to reduce cya (except from ammonia due to foreclosure stagnation

) is to drain, just so you know.
Liquid chlorine is the only way to avoid adding anything other than chlorine. Cal hypo adds calcium and trichlor or dichlor both add cya. So because you're already at 80, if you now use any stabilized products, you'll be increasing your cya and making your water balance much more difficult. The shoe "BBB" philosophy of this site is predicated on knowing and using the correct ratio of cya to free chlorine level so that you stay in control, which usually means avoidance of using stabilized products like the trichlor pucks.
STAINING --
After a foreclosure recovery, some of your stains will be tanin from the leaves, and some can be calcium and some tougher ones can be from metal content such as iron, magnesium, copper etc. that oxidizes from the shocking/slamming required to clear up the water.
In this instance, the tannin type stains will often fade/go away after a season of sun and proper chlorine levels.
My pool is vinyl, so I don't know a lot about calcium scaling, but other posters can chime in about the csi index or you can read in pool school he to manage same.
pool-school/calcium_scaling
For metals, if you used Metal sequestrate during recovery, you may want to top that up again now, and keep your ph on the lower end of the scale, and make sure you combat ph rises with muriatic acid to avoid having more metals oxidize.
To remove historic/existing stains, you may first want to read about stain identification to determine what you're dealing with. For iron, for example, there is a treatment with Ascorbic Acid that can remove them...the process is chronicled in various locations around this forum. You can used a crushed up vitamin c, which IS AA, and hold it to a suspicious stain. If it lightens it, it is a metal stain. If not, it's tannin/organic.
To start learning about stains, you can start here
pool-school/metal%20stains
To see pictures of different types of stains, I found this helpful
http://www.jacksmagic.com/for_homeowner ... brary.html
This is all a lot to cover so first, cn you please post your full test results for water balance and tell us what method you're currently using to maintain the pool? Then we can help hone in on suggestions to address and prevent any future problems or staining.
Congrats on your awesome recovery and welcome to the swamp alumni club

Stick around this forum and soon you'll get the full trouble-free experience
