CYA longevity

[DonnieTheMan]

Ok. So my CYA is pretty high in my pool. I did the regular test and the test where you mix pool water and faucet water. My CYA is around 120-140. My pool is blue as can be and my FC is at 3. We won’t be using the pool again until around April or May. So my question is how long does CYA take to dissipate? I know it stays in the pool for a long time, but what I guess I’m trying to avoid is draining around 75% of the pool. My thinking is if I wait until April or May, I won’t have to drain as much. Am I right in thinking this?

 

[Dirk]

Sort of. With CYA that high and an FC of only 3, your pool is virtually unprotected by chlorine. You're getting away with that because it's so cold. If you wait too long to correct either number, you're risking an algae outbreak as soon as it starts heating up next Spring. The cost of the chlorine to clear that up will likely be significantly more than the water exchange of a 6K gallon pool.

What is your worry about changing the water? Cost? Pool structure? Fill water source?

By the way, a pool that is "blue as can be" does not mean it is sanitized, or safe for swimming.

 

[Oly]

You will want to drain some and refill well before the water temps get to 60f and algae becomes an issue. The CYA may drop some over four months but it will not be significant in a normal situation at your current numbers. I would consider expected rainfall, fill water availability, drain water location along with any needed equipment and your time availability. If using municipal water/sewer check if they set usage and pricing rates on a scheduled one month use to avoid a season long water and sewage usage increase.

 

[DonnieTheMan]

Sort of. With CYA that high and an FC of only 3, your pool is virtually unprotected by chlorine. You're getting away with that because it's so cold. If you wait too long to correct either number, you're risking an algae outbreak as soon as it starts heating up next Spring. The cost of the chlorine to clear that up will likely be significantly more than the water exchange of a 6K gallon pool.

What is your worry about changing the water? Cost? Pool structure? Fill water source?

By the way, a pool that is "blue as can be" does not mean it is sanitized, or safe for swimming.

I have plenty of chlorine so that’s not really a issue. I’m actually going to add some more this evening to bring it back up to 6 or 7. I bought a 100ft backwash hose and a submersible pump to make the drain process a lot faster. Again I guess I’m just trying to avoid draining and refilling so much water. It won’t affect the bill too much, so I guess I just need to do it and be done. So draining about 75% of the water should be good? I believe that’s about how much I drained last time when those stupid pucks caused my CYA to rise so high.

 

[DonnieTheMan]

You will want to drain some and refill well before the water temps get to 60f and algae becomes an issue. The CYA may drop some over four months but it will not be significant in a normal situation at your current numbers. I would consider expected rainfall, fill water availability, drain water location along with any needed equipment and your time availability. If using municipal water/sewer check if they set usage and pricing rates on a scheduled one month use to avoid a season long water and sewage usage increase.

We are allowed to refill a pool once in a calendar year. I just had to do this back in June I believe, so they won’t comp this next refill. It won’t impact the bill too much though so I guess I’ll be draining it this weekend. I did purchase a 100ft backwash hose and a submersible pump vs using a water hose like last time. Took like 3 or 4 days for the pool to drain lol

 

[Dirk]

Problems solved! Do pay attention to our CYA chart to correctly dose your pool with chlorine.

The Free Chlorine and Cyanuric Acid Relationship

Managing your cyanuric acid and Free Chlorine levels is key to stabilizing your pool. Learn how these two items affect each other.

www.troublefreepool.com

 

[DonnieTheMan]

Problems solved! Do pay attention to our CYA chart to correctly dose your pool with chlorine.

The Free Chlorine and Cyanuric Acid Relationship

Managing your cyanuric acid and Free Chlorine levels is key to stabilizing your pool. Learn how these two items affect each other.

www.troublefreepool.com

I have that saved on my as a screen shot!

 

[an1vrsy]

I have plenty of chlorine so that’s not really an issue.

Are you going to use pucks or liquid chlorine? You should really think about getting a SWG or use LC so you’re not in this same boat next year.

 

[DonnieTheMan]

Are you going to use pucks or liquid chlorine? You should really think about getting a SWG or use LC so you’re not in this same boat next year.

I use LC. Pucks caused me too much trouble.