CYA addition reading way higher than expected

[Rogue959]

Fc 6.5
ph 7.2
ta 60
ch 450
salt 3500
bor 35
cya 100 ( was 20 and added 3kg cya , was expecting around 60)

added 3kg of cya and got more than expected . Thoughts?

 

[riley00dog]

Hi from Brisbane [emoji1309] Did you use pool maths to get your amount of cya to add? I notice you use the ccl test kit. There have been some problems with the cya standard and I think older reagents. If you got your amount to add from pool maths and your pool volume is correct, I would contact ccl to see if you might have a faulty cya reagent before panicking.

 

[Jezza]

With those results you are in plaster etching territory.

Just having a play around with Poolmath, you could use some baking soda to bring your TA up to say 80 which should help to bring your pH up as well. With a pH of 7.8 and TA of 80, it allows you to stay above -0.6 with the variable of water temperature which could reflect anything from 0 degrees C -20 degrees.

I'm just wondering if you might be even higher with CYA- hopefully by not too much if you were around 20 and then added with what you thought was aiming for 60. Just in case it is higher maybe run the diluted CYA test- use a water sample with half tap water and half pool water and then multiply your result by 2.

Otherwise if you are running at CYA you need to always make sure your FC never drops below 5- so targeting and maintaining 7-8 should give you some leeway.

I agree with Riley- check first with CCL

 

[Rogue959]

Seems all is fine with ccl kit and standard . I’m lost

 

[mknauss]

How long did you let the CYA mix before testing? Testing a level of 20 ppm is pretty difficult. Could your CYA have been higher before adding your new batch?

Take care.

 

[riley00dog]

Seems all is fine with ccl kit and standard . I’m lost

Hmm, was worth checking. I’m not sure what could have happened. Our pool is about 25,000 litres so around 6,600 gallons. They dumped two bags of 1kg cya at start up and we have a cya of 80. This is spot on as per pool maths as it states 1kg will raise my cya by 40. Your pool is 3 times the size so 3kg should have raised your cya by about 40 give or take.

 

[Rogue959]

so after some further investigation with ccl they are now getting the same results as me with the new standard and new agent with the dot disapearing at 80.

they are rectifying it.

they have been super helpful!!

thanks all