Does my CH need addressed?

[CountryBoy19]

FC: 7.0 (just coming down from a shock)
CC:0.5
pH:7.0 (dropped from 7.5 to 7.0 overnight)
TA:160
CH:50

Pool is fiberglass so it's not a concern for leaching calcium but it seems like I'm always fighting to keep my pH up.

At the same time, won't adding acid w/ aeration to get TA down further reduce my CH?

Chemistry isn't my strong suit...

 

[mknauss]

Recommended Levels
250 ppm CH is recommended as it is recommended by most fiberglass manufacturers and it keeps cobalt staining from happening.

Adding acid does not reduce CH. Only removing pool water and replacing it with lower CH water will reduce CH.

Your pH should rise quickly with a TA of 160.

What is your CYA?

 

[CountryBoy19]

Recommended Levels
250 ppm CH is recommended as it is recommended by most fiberglass manufacturers and it keeps cobalt staining from happening.

Adding acid does not reduce CH. Only removing pool water and replacing it with lower CH water will reduce CH.

Your pH should rise quickly with a TA of 160.

What is your CYA?

CYA is 32

It looks like the only way to increase CH is to add calcium chloride salt...30 pounds of it according to pool math. Will that make the water salty?

 

[mknauss]

Calcium chloride will not make your water salty.

Your signature says the pool needs a new gel coat. If it is in rough shape, I would not add the calcium. It is a preventative to staining. If you do not care about the looks, do not add it.

What test kit are you using? Please add that to your signature.

 

[CountryBoy19]

Calcium chloride will not make your water salty.

Your signature says the pool needs a new gel coat. If it is in rough shape, I would not add the calcium. It is a preventative to staining. If you do not care about the looks, do not add it.

What test kit are you using? Please add that to your signature.

TF-100 kit.

I patched the gel coat spring 2017 and I haven't seen any new bubbles in it (but I also haven't drained it to inspect closely either).

Just so I'm understanding right, the reason for increased CH is to prevent staining. Right? I'm not super concerned about staining, I just thought CH may play a role in the pH. Am I off track on that?

 

[mknauss]

Just so I'm understanding right, the reason for increased CH is to prevent staining. Right? I'm not super concerned about staining, I just thought CH may play a role in the pH. Am I off track on that?

CH in a fiberglass pool is primarily about staining. Some gel coat also has calcium in it that needs protection but that is typically in very old FG pools.

CH has no effect on pH.

 

[CountryBoy19]

CH in a fiberglass pool is primarily about staining. Some gel coat also has calcium in it that needs protection but that is typically in very old FG pools.

CH has no effect on pH.

Thanks for all the advice.

So if my pH keeps going down, even though TA is high, should I just leave TA high?

 

[mknauss]

The pH only goes down if you are adding acid or acidic products, like trichlor or dichlor. Are you?

 

[CountryBoy19]

The pH only goes down if you are adding acid or acidic products, like trichlor or dichlor. Are you?

I did add CYA last night when it dropped .5 in pH but this is an ongoing issue. I've fought continuously dropping pH every season even though my TA is high...

 

[mknauss]

Again. pH only goes down if adding acid or acidic products. It cannot naturally decrease.

 

[CountryBoy19]

Again. pH only goes down if adding acid or acidic products. It cannot naturally decrease.

CYA is an acid, does it have an effect on pH? That could explain the large overnight drop.

The "regular season" drops are less drastic. Usually only dropping around 0.3 over the course of a week. I'm definitely not adding any acid products during that time. Once I get CYA balanced after opening the pool I don't add anymore acid products. Just liquid chlorine and pH-plus. I have an automatic cover so my chlorine consumption is really low and I can't see any environmental factors that could be throwing things off...

 

[mknauss]

CYA is an acid, does it have an effect on pH? That could explain the large overnight drop.

Correct - I was replying to your saying the pH continually drops.

Fill water? What is the pH of the fill water?

 

[CountryBoy19]

Correct - I was replying to your saying the pH continually drops.

Fill water? What is the pH of the fill water?

Because the cover keeps evaporation to a minimum I usually only have to add water once or twice during the season.

But I would say my fill water is a bit acidic because it is rainwater.