Apologies for the delay in responding and I appreciate the advice.Continue with your startup and see where your water chemistry lands after about 2 months.
You are correct that to lower CH you will need to drain water and replace it with lower CH water.
Your high CH may be due to lots of plaster dUst in the water that your filter will remove in the coming days.
Be patient.
Your water softener salt has nothing to do with warning of not adding pool salt into the water. Water softener salt does not get into the water in significant amounts.
Plaster Installation and Maintenance - Further Reading
www.troublefreepool.com
When Should Salt be Added? In our industry, there seems to be some consensus to wait 30 days before adding salt to new plaster pools, yet some say it is okay to add salt within a couple of days of filling the pool. Who is right? This thread describes why it appears that the recommendation to wait 30 days before adding any salt is appropriate for most plaster pools, including quartz and pebble pools.
Post a complete set of water tests for your pool...
FC
CC
pH
TA
CH
CYA
SALT
WATER TEMP
CSI
and your fill water...
pH
TA
CH
FC: 3
CC: 0
TC: 3
pH: 7.5
CH: 550
TA: 80
CYA: 25 (expect this to go up, sock is in pool as we speak)
Temp: 67
CSI: 0.01
I do not have anything as of now to accurately test the salt. When we purchased the hose the SWG had already gone kaput and we used liquid chlorine for the last half of the summer after we moved in. The automation system included says salt is at 0 ppm but im not convinced its accurate.
I have thus far been unable to get a water report from the company who filled it. It seems they have left early for memorial day weekend.