I think that we do have very hard water here in Arizona. We do have a water softener if that matters.
I ran the CH test that Bperry recommended and I got a CH of 375. Looks like that is in range, but I'm having trouble adding it to PoolMath for some reason.
In the free version of PoolMath you can add only one log entry, so you have to keep overwriting this.
Better to just get the subscription - looks like you have already done this.
Your CSI now looks quite high because of the pH which is potentially showing false high because of FC above 10. But with TA at 100, pH likely is high. If you have distilled water (this is important), you can make a 50:50 diluted sample and test this. The distilled water will not change the pH, but halve the FC to 10.5, which should just be low enough for a pH measurement if you do it fast - the pH reading might still drift slowly up.
But more important to deal with the algae you were mentioning, it is unlikely that two one-time shocks got rid of them. FC needs to be at "shock" level for an extended period to really finish them off. The process is called
SLAM Process, for "Shock Level And Maintain". The "Maintain" is important.
With CYA 90, your SLAM FC is 34, which is a challenge to maintain, but might be possible in winter. Usually, we recommend to reduce CYA first to make the SLAM easier.
But first you should do an
Overnight Chlorine Loss Test, so we know if that algae really still is there.
CH 375 is good. CSI will be in range with a little pH/TA adjustment. But let's deal with the algae first. And potentially the CYA.
