Hello All:

I thought I'd post a new thread for this one. It looks like my "Chlorine Lock" is over thanks to all of you. Also, following your advice I ordered and received my Taylor k-2006 test kit and love it. I'd like it if someone could do a little hand holding for me as I don;t want to screw up and I'm not exactly full of confidence yet. Here are my vitals according to my new kit:

1. Free Chlorine 1.6 ppm
2. Combined Chlorine 0.4 ppm
3. pH 7.4
4. Alkalinity 180
5. CYA < 30 ( I could see the black dot when it was completely full!)
6. Calcium Hardness 220
16 x 36 24000 vinyl in-ground with Hayward EC 65, 1 skimmer and 3 returns

My first questions is that I am backwashing and adding DE and my circulation is slowing down and pressure up to about 24 pretty quickly. When I backwash my pressure drops to around 12. Can this be due to my CYA? I seem to remember something about that in the Taylor book.

Second, I believe my CYA and my alkalinity are connected. How much of what should I add to get my CYA up a little?

Thanks everyone,

Bill