When to Shock?

[tcjones]

As a recent Baq to Cl convert, I need some advice on when I need to shock now that I am using chlorine.

With the Baq, is seemed everytime I had the water tested, I needed to add shock (27% hydrogen peroxide).

Now since "shock" in the Cl realm is an activity (raise Cl levels up above 10ppm for a certain time frame) and not product (hyd perox), I need to know when to shock, to what level, and for how long.

Thanks in advance.

tcj

[CarlD]

Based on your CYA (stabilizer) level, you need to maintain a residual FC (free chlorine) level. If you go below that, shocking may be necessary.

Also if CC (Combined Chloramines) goes above 0 (actually, .5 or higher) it's also a good time to shock.

But if your FC is good, your CC is 0, and your water is clear, there's no need.

See the Best Guess table for FC and shock levels at given CYA levels.

[tcjones]

Right now I have FC of 0.5 and TC of 1-2, giving me a CC of more than 0.5, so it looks like shocking is in order. According to the best guess CYA, my shocking level is 15, which calculates to 2 1/2 large bottles of Bleach.

My question is, do I just bring the FC up to 15 ppm and let it return to normal, or do I keep adding until I can to maintain 15 ppm overnight?

[duraleigh]

My question is, do I just bring the FC up to 15 ppm and let it return to normal, or do I keep adding until I can to maintain 15 ppm overnight?

overnight

[tcjones]

overnight

Dave, I just wanted to check, you say "overnight", as in, keep adding until I can maintain shock level overnight?

[duraleigh]

Dave, I just wanted to check, you say "overnight", as in, keep adding until I can maintain shock level overnight?

Yeah, sometimes I sacrifice clarity for brevity.

If you can hold Cl levels overnite, not dropping more than 1 maybe 2ppm, that will tell you you have finished killing the organics in your pool.

Only AFTER that occurs should you let your Cl go back to maintenance levels.

[tcjones]

d - thx - t (now that's brief )