I have a spa that I am trying to keep CYA free since it is indoors and there is no need for CYA, right?
Well it has been drained twice now. I have the TF test kit and the CYA was over 100 when first drained. After draining it showed 0. About a week later I tested and it showed a CYA of 40 again. I drained it again and tested the refill. It showed 0. Well here we are again a week later and it is up at 30 now!
What gives? I am using BLEACH, MA, Baking Soda, and 20 mule team Borax. It has a cartrigde filter and that was rinsed off the last drain.
So where is the CYA coming from?http://www.troublefreepool.com/posti...ode=post&f=10#