Hi -

I tried searching the forums but couldn't find an appropriate answer to my question. I have a vinyl in-ground pool and am getting conflicting information about what type of chlorine shock to use.

I was concerned about handling/storing liquid chlorine and found the Lithium Hypochlorite to be very expensive, so at the advice of my local pool store I have been using bags of Calcium Hypochlorite. I am very concerned about bleaching and/or weakening of the liner, so I have diligently tried to dissolve the powder in a bucket before adding to the pool, but always have a residue collect in the corners of my deep end hopper. I just read elsewhere today that I should pre-dissolve and then just pour the liquid into the return stream, disposing of any remaining solids. (My pool store never mentioned about the disposal of the solids).

Can you confirm that Calcium Hypochlorite is appropriate and safe for vinyl liners if pre-dissolved? What is the residue and I can I just throw it away? Are there any other products that I should be considering? Incidentally, I concurrently use a floater with 3" tabs.

Thanks.

Jim