We have a 9 year-old, 18,000 gal, in-ground, concrete/plaster pool in the High Desert of CA that I took over the full maintenance of in June. Previously a variety of "Pool Guys" used tri-chlor tabs and who knows what else to keep the water clear and reasonably algae free. It was drained two years ago for what I understand now must have been high CYA levels (at the time I think it was explained to me as "chemical levels so high that adding more chemicals does no good"!?!).

I did my homework prior to joining PoolForum by reading just about everything on PoolSolutions. I have pulled out the tri-chlor and now use only LC for sanitation.

Here are my most recent numbers:

ph: 8.0
TA: 135
CH: 390
CYA: 100

The CYA is slowly dropping and I have been using muriatic acid to try and keep the pH below 8. I've had the chlorine as high as 3 but it has been a struggle to get it any higher. The water is clear and any algae that appears is easily brushed away.

Should I just continue to try and keep the pH down and the chlorine up or is there something I am missing here?

Thanks again for all of the great info and advice.