high cya

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Hi everyone,

I've just started doing my own chemicals and need help. I have a vinyl-lined 29,000 gal pool, SWG. Have had a SWG x 2 yrs. Just got a new cell; old one never really read things correctly.

My chemicals have been off for a month. Today, ph 7.1, FC 0.5, CC 0.5, T/A 100, CYA 110.

I've used the pool calculator, but was trying to avoid draining the pool.

Per the calculator, I've added dichlor daily for the past 2 weeks to get FC up daily. I'm not sure if I should shock, or to drain to lower CYA. What problems result from elevated CYA?

 

[woodyp]

Biggest problems are having to maintain a much higher level of FC in the pool to achieve the same results at a lower cya value. See the chlorine/cya chart in pool school to see how much those shock values have to be at high levels to kill off "problems".

 

[Siamese]

Welcome to TFP!

Two quick questions -- first, how did you get your test results, I assume its a pool store reading. The pool stores are notoriously bad at measuring CYA, so their reading of 110 may be much higher.

Second, how does your water look?

Let us know and we can figure out a plan. Unfortunately CYA doesn't go away by itself, so a partial drain may be in order.

 

[duraleigh]

Welcome to the forum :lol:

I've added dichlor daily for the past 2 weeks to get FC up daily.

1. Stop using dichlor....that's what's caused your CYA to be high.

2. Put Clorox in your pool to get your FC up......the pool calculator will tell you how much you need to elevate your FC to about 10ppm.

3. Reduce your CYA down to 50ppm by a series of partial drain and refills.

 

[Butterfly]

Hi everyone,

I've just started doing my own chemicals and need help. I have a vinyl-lined 29,000 gal pool, SWG. Have had a SWG x 2 yrs. Just got a new cell; old one never really read things correctly.

My chemicals have been off for a month. Today, ph 7.1, FC 0.5, CC 0.5, T/A 100, CYA 110.


I've used the pool calculator, but was trying to avoid draining the pool.
The problem with CYA tests is that they are accurate up to 100 and can read anything over 100 as 100. Is your CYA test of 110 a result of a dilution test? You can dilute your pool sample with half pool water and half tap water and double the test results. Less accuracy, but you would know if it is closer to 100 or 200.

Per the calculator, I've added dichlor daily for the past 2 weeks to get FC up daily. I'm not sure if I should shock, or to drain to lower CYA. What problems result from elevated CYA?
As mentioned, it is difficult to maintain a pool with that high a CYA. Shocking the pool to that level of CYA would be expensive and difficult. And, as Dave said, the dichlor is what increased your CYA. Any time you need extra chlorine beyond what the SWG can produce or if you need to shock, use liquid chlorine/bleach because it has less/no side effects.

Recommended CYA levels for SWG's is 60 to 80. See 'water balance for swg's in Pool School.
pool-school/water_balance_saltwater_generator

I suggest you do the drain/refill dance and lower the CYA to about 80.
Then retest and adjust from there.

It would be helpful if you add your pool and equipment specs in your sig.
Go to User Control Panel (top left under TFP logo) select Profile, then Edit Sig.
This will help folks help you

Welcome to the forum

 

[[email protected]]

Im testing with a home kit - TF-100 I got thru this site. So I used the CYA view tube and all. I was wondering if the dichlor was the reason. Has it always raised CYA? Any suggestions on how many inches/feet to drain if this is the case?

 

[anonapersona]

Pool Calculator will tell you, enter current CYA and goal, with correct volume of pool.

 

[Richard320]

Im testing with a home kit - TF-100 I got thru this site. So I used the CYA view tube and all. I was wondering if the dichlor was the reason. Has it always raised CYA? Any suggestions on how many inches/feet to drain if this is the case?

Yes, dichlor is the reason. Every ounce you added, added more CYA.

The easiest way to figure out how much to drain is to pick a target. Then figure out what percentage that is. say you want 70; you're at 110. 70/110 is 63%. So you need to drain 37% of the water. But how much is that? If you can figure out your average depth, it's easy. My pool average depth is 60 inches - yours will be different - so if I want to lose 37%, I'd pump out 22 inches. .37*60.