How often to test CYA?

[joecoyle]

In learning TFPC, I have a question about CYA. I know it shouldn’t fluctuate unless you add di/trichlor or CYA directly to the pool but how often should I be testing for it? If my F.C. is dependant on CYA then it would make sense to test it weekly?

For example my CYA at last test, last week was 50 and my F.C. today is 4.5. Accordingly to the chart it’s on the low side so I’d like to add some bleach to get it up to 6. But what if my CYA isn’t still 50? We’ve had a solid 4 days of rain!

I need to get into a habit of what to test when.

Do people test F.C. using FAS-DPD daily or just use the OTO test for a daily check? Seems like I’d burn through reagents and powder if I was doing that daily. And at $90 for a full refill kit inc shipping I don’t fancy buying too often.

Thanks
Joe

 

[jblizzle]

Rain can impact the CYA if the pool overflows or you partially drain. So retesting after such an event is a good idea.

Some use the FAS-DPD chlorine test daily, others maybe only weekly using the OTO more often. Depends on how comfortable you are with your pool and maintenance.

Reagents should be replaced every 1-2 years anyway. FYI, there is a sale in March for TF-100 refills for under $40. Even without the sale the refill is not $90 plus shipping.

 

[joecoyle]

It is when you have to ship it to the US. Then ship it to the UK. Then pay customs charges! Expensive much!!

I’ve not needed to drain the pool yet because of the rain so maybe it’ll be ok. It’s still hammering down now! Stupid English weather. ️

 

[zea3]

Usually you can test CYA monthly once it reaches the level you want. It is good to check it after heavy rains when the pool overflows to make sure you haven't lost too much.

For now test your FC daily using the FAS/DPD test. Once you get a good feel for how much chlorine you use on a daily basis you can use the OTO for daily testing and the FAS/DPD weekly.

You may want to consider our new PoolMath app for Android and Apple .

 

[Topher55]

Cya is only lost through draining, splash out, and backwashing. not evaporation. I test mine every few months unless I am pumping out a lot of water.

I'll test TA and CH once a month unless I suspect a problem with it.

I test the FC and PH most often, I bought large bottles of the reagents on amazon, a pint of the liquid and .25lb of the powder a few years ago and still have plenty. I store them in a cool dark place and haven't had any issues.

 

[jblizzle]

Sorry, did not see your location driving up shipping costs.