Which to do first, shock or increase TA?

[derekb41]

Newbie here and I just opened my first pool. 15k gallon gunite with DE Filter.

Here are my water results:

Total Hardness: 250
Total Chlorine: 1
Free Chlorine: 1
pH: 7.2
Total Alkalinity: 40
CYA: 70

So, do I shock first, then later add baking soda to raise my TA? Or do I increase my TA first, then shock?

Thanks in advance.
Derek

[Watermom]

I would shock first. (What are you using to shock with?) Actually, it doesn't hurt to add bleach and then a little later, some baking soda. It doesn't have to be days later. Keep an eye on your ph. 7.2 is fine, but you don't want it any lower. Also, since your cya is already 70, you should stick with liquid chlorine instead of trichlor tabs as they will increase your cya level even more.

[derekb41]

I would shock first. (What are you using to shock with?) Actually, it doesn't hurt to add bleach and then a little later, some baking soda. It doesn't have to be days later. Keep an eye on your ph. 7.2 is fine, but you don't want it any lower. Also, since your cya is already 70, you should stick with liquid chlorine instead of trichlor tabs as they will increase your cya level even more.

Thanks for the response. I have cal-hypo 73% that I planned to shock with. I ditched the trichlor tabs, as you mentioned, because my cya was at 150 prior to drain/refill. Just bought lots of liquid clorox 6% to use as part of the BBB method.

[Watermom]

Since you already have it, go ahead and use your cal-hypo. But, in the future, I would just use bleach for your daily chlorination and shocking. Your calcium hardness levels are already at appropriate level and you don't want it too much higher.

[derekb41]

Since you already have it, go ahead and use your cal-hypo. But, in the future, I would just use bleach for your daily chlorination and shocking. Your calcium hardness levels are already at appropriate level and you don't want it too much higher.

Thanks. What's the highest I should let my CH reach before I stop shocking with cal-hypo and begin shocking with bleach? I hate to discard good cal-hypo if I don't have to.

[aylad]

Usually when your CH starts approaching 300 or higher you will begin to start having problems with milky looking water that won't clear, especially when your TA and pH rise. It's different for every pool, but I wouldn't let it get over 300.

Don't throw the cal-hypo out--it keeps fairly well, and there's always next year....or later in the season if you have as much splash out as I do!

Janet