BBB method with a semi permanant cover

[bsimo57]

I am converting a friends pool to BBB. It is an inground vinyl, 36k gallons. He has a automatic solid cover that is on at all times except when swimming. Since he shouldn't lose much fc to sun what would the ideal cya level be. We have it at 25ppm right now and wasn't sure if we should bring it up.
Thanks

 

[harleysilo]

Is his pool a saltwater pool with a SWG?

 

[bsimo57]

No, normal pool. Was using triclor and all the other pool store stuff.

 

[RobbieH]

I'd think 25 is fine, but I'm concerned the CC won't get burned off without any sun. Opinions from the experts?

 

[duraleigh]

25ppm CYA is adequate just fine but I think RobbieH makes a good point about letting the sunshine onto the pool for a few hours each week.

 

[harleysilo]

25ppm CYA is adequate just fine but I think RobbieH makes a good point about letting the sunshine onto the pool for a few hours each week.

Wouldn't that happen with normal swim time? I thought appropriate FC levels would take care of CC regardless of sun exposure. I havent read about neccesary uv exposure time to burn off cc.

 

[JasonLion]

Normal swimming may well be plenty of sunlight. You only need a couple of hours a week. Chlorine alone, without any sunlight, is not always enough to get rid of all the CC. Chlorine and sunlight work together to get rid of CC. That is one of the things that makes indoor pools challenging. If CC is staying at zero there is nothing to worry about, but if CC goes up, you know you need more sunlight (and adequate FC levels).

 

[harleysilo]

Good to know thanks Jason!

 

[bsimo57]

Another question concerning the cover. We have been shocking for 3 days and leaving the cover on, probably only getting 1 hr of sun a day. Should we be leaving the cover off for several hours a day until we pass the 3 tests?

 

[duraleigh]

Should we be leaving the cover off for several hours a day until we pass the 3 tests?

What are your current results? Do you have CC's?

 

[harleysilo]

What does the cover manufacture say about leaving pool at shock level covered? Risk of damaging the cover?

 

[bsimo57]

As of noon today we look like this.

fc - 16
cc - 0
ph - 7.8
cya 30-40 (added approx 1 lb last night)
ta - 325 (going to work on this next week)

pool was looking real good at noon. We left the cover open all morning and I am going to check things again @ 3pm. Want to see how much fc is lost when we leave the cover all the way open.

 

[JasonLion]

Very pretty!