Yes our testing kit only goes to 100 CYA, but the pool tech we consulted had a kit that went higher and he was the one he told us it was 150.

Sounds like we should go ahead and drain the pool. The pool is an inground concrete pool about 10 years old in a warm California climate. We are novices as this is our first pool - any advice on how to best drain the pool? Anything we need to look out for to avoid damaging the pool? Should we use a pressure washer once the pool is drained?

Thanks for all your help.