Thanks for your help @duraleigh and sanity checks. I ask other pool owners around me and they seem to know less than I do so clearly its the blind leading the blind with everyone going off the pool companies around here.Sure, I would leave the pool cover off from time to time anyway. Disregard weekly backwash......don't waste the water......use the 25% rule.
If you want, you can construct a drain from your roof gutters into the pool. Free, reasonably easy if you're hand and guaranteed to work. Will bring down your TA and CH.
JohnT lives in your region and his TA is really high, too, I think.....maybe 250-300. He deals with it nicely so perhaps he can post up or you could send him a PM
I was told to use muratic acid to get the build up off my SWG, but learned here that it will lessen its life. So what does cause the build up? CH? TA? all the above?
@JohnT - What do you do to manage your TA?