SWG occasionally brings chlorine to 0

[Talshum]

Hi! Newbie with a mediocre pool guy
My pool’s chlorine goes to 0 very often. Maybe once a week. I have a pool cover and the swg is set to 40%. We use the pool couple of times a week but not too much every day. Pool temp is around 85~ this season (and no heating). I tested the pool today after 1 day of 100% boost to bring back the chlorine. What can cause the chlorine go to 0 so easily? Pic attached. Thanks

 

[mas985]

What can cause the chlorine go to 0 so easily?

Algae. Run an Overnight Chlorine Loss Test

 

[jgofnj]

For one (of many issues) your CYA is way too low.

 

[tucsontico]

Tell us more about your pool, e.g., total volume in gallons, which SWG, how do you test your water, etc. From your limited info, I can see the CYA is way too low for an SWG pool. The FC is being burned off by the sun and you most likely have a beginning algae bloom due to the low FC levels. You need to get liquid chlorine in your pool today to raise the FC to at least 5 ppm (8-10 would be better). Then bring your CYA up to 60-80 ppm. Please read our Pool School info:ABC's of Pool Water Chemistry

 

[Talshum]

Tell us more about your pool, e.g., total volume in gallons, which SWG, how do you test your water, etc. From your limited info, I can see the CYA is way too low for an SWG pool. The FC is being burned off by the sun and you most likely have a beginning algae bloom due to the low FC levels. You need to get liquid chlorine in your pool today to raise the FC to at least 5 ppm (8-10 would be better). Then bring your CYA up to 60-80 ppm. Please read our Pool School info:ABC's of Pool Water Chemistry

Thank you! Not sure which swg I think Jandy? 8000gallons .
I test with the kit recommended here (trouble free? Not the Taylor one). I put chlorine and boosted to 100% and I have more FC. Sounds like the cya is the culprit? I have a pool cover so not much sun tbh

 

[proavia]

Use liquid chlorine to get your FC up quixkly.

Add stabilizer to get your CYA to 70 *after* an Overnight Chlorine Loss Test

Chances are your low CYA is causing the FC to burn off rapidly. A SWG produces chlorine slowly - it's good for maintaining FC if CYA is in range. It isn't good at increasing FC quickly.

 

[Talshum]

Use liquid chlorine to get your FC up quixkly.

Add stabilizer to get your CYA to 70 *after* an Overnight Chlorine Loss Test

Chances are your low CYA is causing the FC to burn off rapidly. A SWG produces chlorine slowly - it's good for maintaining FC if CYA is in range. It isn't good at increasing FC quickly.

Why my pool guy doesn’t even check cya? Poor professional or none of them testing? Thank you

 

[cwswifty]

Why my pool guy doesn’t even check cya? Poor professional or none of them testing? Thank you

That's a question for your pool guy. Better yet, just issue him his walking papers and begin taking care of your pool yourself! This group is here to help you.

 

[proavia]

The question is - why even have a pool guy?
You have a SWG
You have one of the best test kits available
Your pool is easy to maintain

Test chemicals
Adjust pH if needed with muriatic acid
Monitor and adjust your SWG as needed to keep FC within range for your CYA FC/CYA Levels
Empty skimmer baskets, brush and vacuum as needed
All this would take 30-45 minutes of your time per week - maybe less
And no one will care for your pool as good as you will

Chances are your pool guy stops by once a week for maybe 10 minutes max and charges you good money for not correctly maintaining your pool. And then when something goes wrong, he will charge you more to fix his lack of care. Most pool service's business model is in/out as quickly as possible and hope the pool still looks good the next week. Most don't take the time to test correctly.

 

[Talshum]

The question is - why even have a pool guy?
You have a SWG
You have one of the best test kits available
Your pool is easy to maintain

Test chemicals
Adjust pH if needed with muriatic acid
Monitor and adjust your SWG as needed to keep FC within range for your CYA FC/CYA Levels
Empty skimmer baskets, brush and vacuum as needed
All this would take 30-45 minutes of your time per week - maybe less
And no one will care for your pool as good as you will

Chances are your pool guy stops by once a week for maybe 10 minutes max and charges you good money for not correctly maintaining your pool. And then when something goes wrong, he will charge you more to fix his lack of care. Most pool service's business model is in/out as quickly as possible and hope the pool still looks good the next week. Most don't take the time to test correctly.

Yea you’re right. His relatively cheap so hard to say bye bye

 

[proavia]

Yea you’re right. His relatively cheap so hard to say bye bye

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