Can we swim? Fc 10.5, cya @20

[KaiBee]

Hi. Boys want to jump in after school. My cya is at 20 but may be lower and my fc is 10.5 cc.5. Do I add cya now or let the low cya help bring the fc down? Is that even a thing? Can they still swim? I turned the heater up this morning but now I'm second guessing what my next steps are. Water will be about 74 by the time they get home. Thanks !
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Kai pool
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Build Type: Vinyl
Volume: 21480 gallons
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Latest Test Result Summary:
FC: 10.5 (an hour ago)
CC: 0.5 (an hour ago)
pH: 7.6 (an hour ago)
TA: 80 (an hour ago)
CH: 50 (an hour ago)
CYA: 20 (an hour ago)
SALT: 2400 (an hour ago)
TEMPERATURE: 61° (an hour ago)
CSI: -1.06 (an hour ago)
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[Newdude]

Welcome back Kai !!!!!

Swimming is safe up to and including SLAM level on the FC/CYA Levels. In your case that safe FC level will only increase as the CYA rises over the next day or two. Add it in stages as it’s easy to overshoot with no way of removing besides draining.

 

[mknauss]

With a CYA of 20 or less, the FC will drop rapidly if there is any sun shining on the pool surface. Try to get the FC down to 5 ppm or so before they go swimming.

 

[KaiBee]

With a CYA of 20 or less, the FC will drop rapidly if there is any sun shining on the pool surface. Try to get the FC down to 5 ppm or so before they go swimming.

Ok, but if I add in half the suggested amount of cya (sock method but hurry it along by squeezing then mixing), should they be ok to go in today. Obviously I will test again before they do, but sun is shining and pool is open so you know how that is... not that I think they'll stay in long with water being only between 74 and 76.

 

[KaiBee]

Welcome back Kai !!!!!

Swimming is safe up to and including SLAM level on the FC/CYA Levels. In your case that safe FC level will only increase as the CYA rises over the next day or two. Add it in stages as it’s easy to overshoot with no way of removing besides draining.

Heyyy! I'm thinking I will add in half the suggested cya for now (sock method, squeezing it and mixing in) and in a few days recheck and continue from there. It's the first day with hot weather and pool open so they are anxious.

 

[mknauss]

but if I add in half the suggested amount of cya (sock method but hurry it along by squeezing then mixing), should they be ok to go in today.

Sounds good. Brush the pool really well to distribute the CYA once you get it dissolved.

 

[KaiBee]

Sounds good. Brush the pool really well to distribute the CYA once you get it dissolved.

Will do, thanks!