The lady at the local pool store sold me something to reduce the ph in pools when I went to get my stabilizer, but I have never had to use it. She said I would definitely need it with a SWCG and I didn't know any better than to listen to her. My ph has been consistently around 7.2 since I put the pool up at the beginning of the summer. It never seems to change. That is why I had thought about putting in some Soda Ash to raise the PH a little since is has always been on the low side. I think soda ash also raises the Alkalinity which would knock out two birds with one stone. I just don't know how much to put in. I definitely don't want to overdo it and through the whole thing out of balance.

The instructions for the K2006 test kit says if the CH test starts out purple then there are metals in the water, hence the reason for adding the titrant before the test to tie them up. PoolDoc seemed to think my brown stuff on the bottom of my pool may have been iron so now I am wondering if this proves it. If I need to get it out, what do I use and how much of it?