How to Increase CYA

[mknauss]

Just be sure you stay well above minimum FC. The CYA will decrease some over summer when water temperatures are above 80F, so test it monthly.

 

[MrLeadFoot]

Just be sure you stay well above minimum FC. The CYA will decrease some over summer when water temperatures are above 80F, so test it monthly.

Ohhhh, I see! You're saying to raise it to stay "ahead of the curve", so to speak, for when it drops, so I'm not caught off guard when it's too low, right? Sorry, for being so slow in trying to understand what meant. I think I get it now.

 

[mknauss]

Ohhhh, I see! I think I get it now. You're saying to raise it to stay "ahead of the curve", so to speak, for when it drops, so I'm not caught when it's too low, right? Sorry, for being so slow in trying to understand what meant.

Correct. You need to add enough chlorine each day to raise it by what you lose above target range.

SWCG solves all these problems.

 

[MrLeadFoot]

Correct. You need to add enough chlorine each day to raise it by what you lose above target range.

SWCG solves all these problems.

I didn't mean raising chlorine. I understand about adding enough to compensate for daily loss. I was talking about the CYA. You've been saying to raise to 50ppm because it will drop in hotter weather, and even though it won't save me from having to add chlorine every day, this will help prevent CYA from getting too low before I realize it, right?

But, speaking of chlorine, is it OK to add extra to cover a few days' loss, so I don't have to add EVERY, SINGLE day?

 

[mknauss]

this will help prevent CYA from getting too low before I realize it, right?

It will help. Test CYA monthly.

so I don't have to add EVERY, SINGLE day?

you can try it. But it will not work during summer.

 

[MrLeadFoot]

you can try it. But it will not work during summer.

So, are you thinking even if I add 3x what's needed, all of it will burn off during one day? Unless someone else has done it, I guess there's only one way to find out!

 

[mknauss]

No. You likely will get a couple days if you raise it to SLAM level. You will go through a lot of chlorine.

 

[MrLeadFoot]

No. You likely will get a couple days if you raise it to SLAM level. You will go through a lot of chlorine.

I was thinking that if my target is 4ppm, and I normally need 3 cups of chlorine daily to compensate for my daily loss, if I added 9 cups I would get high enough to last 3 days, but your reply led me to believe that things mist not be quite that linear. So, I just went into Poolmath and see that the higher you want to target, the required amount is more exponential rather than linear. There goes my theory. Bummer, but rather have learned that lesson now than discover after 3 days that I have algae or something, and have to start balancing all over again... Yikes!

 

[mknauss]

24 oz of liquid chlorine (10%) adds 0.7 ppm FC to your pool volume. I really doubt that is your FC loss per day from now until October. Unless the pool is covered 100% of the time during daylight hours or is indoors.

 

[MrLeadFoot]

24 oz of liquid chlorine (10%) adds 0.7 ppm FC to your pool volume. I really doubt that is your FC loss per day from now until October. Unless the pool is covered 100% of the time during daylight hours or is indoors.

Don't know about mid-summer, but over the past week, I've added 3 cups every evening to compensate for my daily loss.

 

[IceShadow]

Last year (without the SWCG) I was able to add a couple of times a week. A gallon of FC every 3 days or so kept me above minimum.

But I’m in a different latitude than you are, so that may not work for someone in sunny CA. ^.^

 

[MrLeadFoot]

24 oz of liquid chlorine (10%) adds 0.7 ppm FC to your pool volume. I really doubt that is your FC loss per day from now until October. Unless the pool is covered 100% of the time during daylight hours or is indoors.

Based on what you said here, I don't don't how this is possible, but I specifically monitored levels before and after adding chlorine several times this week, and logged results that differ significantly. 3 cups took me from 4 to 5.5 ppm. 9 cups took me from 3.5 to 8. I also double-checked my measurements against what Leslie's reported in their test. In fact, I typically only need to add 2-3 cups a day to maintain a level at the high end of the scale. I checked the "effects of chemicals" section in Poolmath, and even if the measurement of my pool is off by 5000 - 7000 gallons, Poolmath still doesn't describe what I am seeing. Is it possible that when there's no chlorine you need use more to get it into the water column, but if you already have a good amount of chlorine present, it takes less to raise it?

 

[mknauss]

More likely your pool volume is off. How did you get that number of 27,495 gallons?

Your data above implies the pool volume is more like half of that number.

 

[MrLeadFoot]

I measured as best as I could, given the very different shape of the pool. I've measured with different methods, including trying to measure it as multiple separate pools (due to shape). Over the years, I've even tried seeing what effects a more conservative estimate of capacity would have, like from 27,495 down to 20,000, but it doesn't make as much of a difference as the large FC discrepancy we're talking about here. And, my capacity being off by 50% is a far stretch. I would think I would have had other issues after all this time if I was that far off. In fact, I would likely not have ever seen algae (that would have been a welcome "issue") because I would have been overdosing on chlorine like crazy, as in continuously being at SLAM+ levels all the time. Also, other Poolmath (and Leslie's) chemical recommendations (acid for PH is one such chemical that immediately comes to mind here) are always spot on.

Wait a minute... this year I switched from Home Depot chlorine to Walmart chlorine because HDX is now 50% higher in price. Maybe somebody screwed up, and instead of 10% chlorine I have 20% chlorine in those Walmart bottles, or something? Yes, I'm reaching, but it's possible. I know that there is 12.5% they sell at pool stores, but plugging 12.5% into Poolmath still doesn't make that much of a difference. So, maybe the quality control at the manufacturer Walmart gets their chlorine from is what's off...by a lot?

I will look at my older logs to see how much chlorine I was adding in the past, although I do know my CYA was also way too high in the past, at some point. I will try to see if I can the point in my logs when I got it under control after my 50% drain last year.

Oops, forgot answer your question: LxWxDx7.5 is the calculation I used. I also tried using the formula for round shapes but I can't remember what that is exactly, maybe 3.14 x R(squared) x D x 7.5. I then added the multiple round calculations for each section of my pool.

 

[MrLeadFoot]

Last year (without the SWCG) I was able to add a couple of times a week. A gallon of FC every 3 days or so kept me above minimum.

But I’m in a different latitude than you are, so that may not work for someone in sunny CA. ^.^

Wow, that sounds like a lot of chlorine to add. It seems like I add a lot less than that when I add on a daily basis.

 

[IceShadow]

It certainly does seem odd. You don't have any other sources of chlorine, like an in-line puck feeder or anything?

 

[PoolStored]

LxWxD

^^^What are these measurements? Can you post a picture of the entire pool?

 

[mknauss]

instead of 10% chlorine I have 20% chlorine in those Walmart bottles, or something? Yes, I'm reaching, but it's possible.

That is not possible.

 

[MrLeadFoot]

That is not possible.

Like I said, I was reaching...

 

[MrLeadFoot]

It certainly does seem odd. You don't have any other sources of chlorine, like an in-line puck feeder or anything?

No, nothing.