Calcium hardness low -- buy granular shock, or wait?

[singerteacher]

I just opened my pool, added liquid chlorine, and tested the water:

FC: .4 (Don't worry, I'm planning to add chlorine!)
CC: 0
pH: 7.4
TA: 100
CH: 140
CYA: <25
Sat: -.4
Temp: 70F

My questions are:
1) Should I throw in some granular shock, to raise my Calcium Hardness? I'd have to go buy some, which is easy enough to do. But maybe as I add tap water over the summer, CH will go up on it's own? I don't want to buy granular shock if I don't have to!
2) I have a bunch of chlorine/stabilizer pucks left over -- should I start using them to add CYA to my water?
3) Any need to adjust the saturation? I know it's within the limits, but I worry.
4) Does 70F water have any effect on these readings?

Thanks for your expert help!

 

[JasonLion]

You have a vinyl liner pool, so you don't have any reason to add calcium (except possibly meeting warranty terms). Likewise, you want to run with a very low saturation index.

Your CYA is low. You can use trichlor/dichlor to raise CYA, but it will take a while.

 

[singerteacher]

I'm relieved that I don't have to worry about those things. I've never raised CYA ... can I buy it cyanuric acid somewhere?

 

[257WbyMag]

You can purchase CYA at any pool store. Many folks here get theirs at Wal-Mart, although my Wal-Mart never has any.

Like Jason said though, there is no harm in using stabilized chlorine sources such as dichlor or trichlor if you have them on hand. Just remember that dichlor adds CYA quite rapidly. In either case, as long as you are aware that they both add CYA and you stay on top of their addition to ensure that you don't end up with too high of a CYA level, you'll be fine.