How long of a wait to add CH after Liquid Chlorine

[isabelo]

How long to wait after putting in Liquid Chlorine to put in calcium chloride (Hardness Plus)?
Also, I am measuring 200ppm, should I even bother bringing it up to 225 or 250?

Thanks

 

[tim5055]

Is your pool vinyl or plaster?

 

[isabelo]

Is your pool vinyl or plaster?

It is plaster (in my footnote?)

 

[Richard320]

I wouldn't add any Calcium at all. Are you filling using softened water? It seems weird that anyone in California would need to raise the CH. Plug all your test results into poolmath, including water temperature. If the CSI is above, say, -0.3, don't sweat it. Odds are it will climb over the season as you lose water to evaporation and refill.

If you're worried about protecting the pool finish or maintaining some kind of warranty, just switch to Cal-hypo to chlorinate a while. Every pound of 73% Cal-hypo will add 4.4 CH. So one of those 12 packs of packets from Leslies would add 52 CH and 74 FC to a pool your size. Just let poolmath give you the daily dose to maintain FC and use the Cal hypo until it's gone. Less than half a bag a day, most likely. Do the math... $21 for the hardness increaser vs $56 for the cal-hypo. The Cal-hypo will also replace 13 121 oz jugs of clorox. Of course, the Cal-hypo needs to be dissolved first, which isn't as easy as just pouring straight from a jug.

 

[isabelo]

Ooops see below.

 

[isabelo]

Thanks Richard. I drained and refilled pool last December due to high CYA and now it is around 40ppm. Most likely, the CH also dropped. I no longer want to deviate from using Liquid Chlorine because of the damage done to my check valves and heater by chlorine tabs not to mention ill effects to chlorine consumption. I also think I have more control just adding calcium chloride rather than Cal- hypo. But yes, I think i'll leave the 200ppm CH there alone perhaps it will rise by itself. Thanks.

BTW here are my test results:
FC = 5.5
PH = 7.7
TA = 90
CH = 200
CYA = 40
Temp = 64
CSI = -0.21

 

[chem geek]

Your CSI is lower mostly because of the low water temperature, but if it rises to 80ºF or more you'll be close to zero CSI which is fine. On the other hand, I don't know if your pH will settle in to being stable at 7.7 or whether it will generally be lower. You might consider opening up your cover during the day to help heat the water and close it at night to prevent cooling from evaporation. Your pool water is a little below the average day/night temperature of 80/55 so exposing it so sunlight during the day should help to heat it.

As for evaporation and refill, you have a built-in automatic pool cover so like my pool you should have virtually no evaporation and refill. Also, the CH for water in San Ramon, CA as shown in the Dublin San Ramon Services District 2014 Water Quality Report, Total Hardness varies from 123 ppm to 449 ppm. CH is usually around 70% of TH so could be from 86 to 314 ppm depending on the source. Historically more water from was from the State Water Project and was low in CH, but with the drought more water is taken from local ground sources so will be higher.

Not all water in California is high in CH because not all water is taken from groundwater well sources. Where I live just north of San Francisco, the Marin Municipal Water District 2015 Water Quality Report shows TH from 68 to 111 where 75% is the former so the CH is around 55 ppm. Likewise, the San Francisco Annual Water Quality Report 2014 (which is also water used for the mid-Peninsula) shows Calcium averaging 11, but in calcium carbonate units that is 27 ppm. It is so low because the water comes from the Hetch Hetchy watershed in the Sierras so is mostly captured rainwater with little dissolving of minerals from rock.

 

[isabelo]

Thank you chem geek for the detailed explanation and information you gave. It definitely gives me more knowledge on maintaining our pool water. You have been extra very helpful.