Numbers check

[ssmith7687]

Jacuzzi j345 1400 litres

temp 104 hot tub in use
temp 100 not in use
ph 7.4
TA 80
Ch 80
CYA 30
FC 9
CC .5

chlorine is 10.25 in strength

Generally 2 bathers approx 9pm. No swimsuit. Not showered after hot tub. Fc falls to around 3. I bring FC back to 9 at 10pm

10am I find I need to add 90 ml to bring FC back to 9. does this seem right?

Around 5pm FC sits around 5

Testing with Taylor 2006

 

[ant 83]

these numbers line up with my experiences.

I always add enough to bring it up to shock FC on the cya/chlorine chart, to give me more leeway on time till the next bleach addition.

Trying to stay in the target FC window would have me adding bleach 3-4 times a day - not practical. Not sure how others accomplish this.

Something else I've found, (seems like I'm the only one who's reported this here at tfp) is that frequent shocking like this oxidizes CYA at a high rate. 1-1.5 PPM per day. If I don't add any dichlor chlorine, CYA will be at zero in under a month. I recommend biweekly CYA testing till a pattern emerges.

 

[jeffchap]

Generally 2 bathers approx 9pm. No swimsuit.

????

 

[ssmith7687]

Thanks Ant 83

I recently tried lowering the temp when the tub is not in use. I lowered it to 97 - 98 and found that the tub consumes a lot less chlorine then it did when the tub was maintained at 100+. I am only adding chlorine once a day now (after tub use)

Last check on CYA, i was still holding at 30

these numbers line up with my experiences.

I always add enough to bring it up to shock FC on the cya/chlorine chart, to give me more leeway on time till the next bleach addition.

Trying to stay in the target FC window would have me adding bleach 3-4 times a day - not practical. Not sure how others accomplish this.

Something else I've found, (seems like I'm the only one who's reported this here at tfp) is that frequent shocking like this oxidizes CYA at a high rate. 1-1.5 PPM per day. If I don't add any dichlor chlorine, CYA will be at zero in under a month. I recommend biweekly CYA testing till a pattern emerges.