jason, or someone who knows, please read this

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teppy

teppy

0
Nov 11, 2007
120
Louisiana
there is a debate, sort of, over at garden web about CYA levels. i gave the info that i got from here about CYA needing to be higher now that i have a SWG. this one person totally shot this down and gave me this link. i really wanted for someone here, since you guys are the one that i have trusted since i got my pool and have never had a problem. the part about TA really got my attention. could this be true and the reason for the Ph spikes? does a high CYA really mask the true TA reading? I will be anxiously awaiting feedback from someone who knows. i am just not experienced enough to know how to sort this out. thanks


http://acsp.biz/page.php?62
 
Well, some of what they say is true.

Their chlorine deactivation chart is misleading. They say "there’s almost no difference in chlorine deactivation between 50 ppm and 100 ppm of CYA". When you draw the chart the way they drew the chart the difference isn't clearly visible. But in practice the difference is obvious. Any number of people here can tell you that they use less chlorine at higher CYA levels, even after raising the FC level to compensate for the reduction in chlorine activity.

Their discussion of TA effects is just wrong. CYA does buffer PH, contrary to what they say. That invalidates much of what they say about TA. It is completely appropriate to count CYAs contribution to TA as part of your TA level.

As they mention, you do need to take the CYA level into account when calculating the calcium saturation index. My Pool Calculator does that automatically, and the commonly accepted procedure for calculating LSI includes that as an explicit step. It is implausible that someone would be calculating calcium saturation and not take CYA into account.

Their ORP paragraph is mostly correct, though the actual situation is worse than what they describe. At CYA levels above 50, ORP automation ceases to function reliably at all, which they don't mention.

They claim that CYA reduces the effects of chlorine, which is quite true. But it is simple enough to raise the FC level to compensate for this effect, as described in our Chlorine/CYA chart at Pool School. Doing that takes care of this issue.

The plaster issues they quote have not be confirmed by subsequent studies. The effects reported by the initial study should have been obvious to everyone, but no one else actually sees the effects they report. It seems most likely that the initial study was flawed in some way. If you read the study, they do not appear to have adjusted the PH to the same level in all of the samples. Most likely they started with a common water supply and then added different amounts of CYA to the individual samples, resulting in significantly lower PH levels for the samples with higher CYA levels. Differences in PH are known to cause the effects they observed.

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CYA doesn't have to be higher when using a SWG. It is just a really good idea to have CYA be higher. Higher CYA levels mean less total chlorine usage, which means the SWG doesn't need to work as hard and the SWG cell lasts longer. It also helps keep your FC levels more stable through the day, which allows you to run at slightly lower FC levels that you otherwise would. The reduction in SWG cell runtime helps stabilize several aspects of the pool chemistry, most significantly it reduces the PH drift caused by the aeration from the SWG cell.

There are some disadvantages to running at higher CYA levels. Most obviously, it takes much higher FC levels to fight algae when CYA is high. But most of the really annoying problems with high CYA levels don't start until CYA reaches levels of 100, or higher, which we strongly recommend avoiding.
 
That's exactly why I don't bother with any other pool sites. I have seen BBB work for others and me. I am good with the effort required to make it work and as far as I can tell, everything preached on this site is based on practice not just theory. It's a big Internet and there will always be an oposing opinion out there, but it's not good enough for me if somebody pastes a link to an article they probably found with Google and has not put that to practice.
 
thanks jason. i definitely value your opinion, and even though i still don't quite get it all, i will leave it at that and just trust what you say. until someone else gives me the information to keep my pool as perfect as it has been, since i got it, and not to mention knowing nothing, nadda about pool care, i will continue to take the advice of you guys here.

like i said, the TA part got to me only because of the way my Ph rises since getting my pool. i thought i would check in about that and get an opinion on this.

there are articles all over the internet about pool water theories that people disagree on. in the end this is the only site where most of the people who really know what they are talking about mostly agree with each other making the advice here more stable for those of us who don't know. and, "the proof is in the pudding" as they say. The way my pool looks is all the proof I need.

Now, if i could just find someone, ANYONE to tell me why i am infested with bugs every morning. No matter if i get them all out every day. Every morning i have an infestation. I know that most pools have bugs, but for some reason, i think mine has more. I'm not kidding. i find literally clusters of those little black bugs that bite in all four corners congregated every morning. I mean it looks like bumps on top of bumps of these black bugs. its really nasty looking. yesterday i got in with the vac hose to suck them up. there were so many that i was getting bitten from the sides and behind and even the front as i was getting them. unbelivable.
 
I assume you have read this:
water-balance-tips-for-a-swg-t3663.html
I will not comment on the link you provided since it contains a lot of half truths and if you have nothing nice to say...

However, since carbonate alkalinity is the main factor in determining how fast the pH will rise from outgassing of CO2 then NOT correcting for CYA will work in your favor with a SWG since, if you keep your CYA at the recommended levels your TA will be lower than you think it is!
(Actually, the TA levels we recommend take all that into account as long as your CYA is also within the recommended range. Also, the usefulness of correcting TA for CYA has been debated in the industry for years and , except for calculating Saturation Index (which itself is of dubious value) the corrected TA is not a useful measurement at all.

Edit: did a bit more checking on that site and they don't seem to know the difference between magnesium and manganese (manganese causes purple stains) and they recommend 'slugging acid' to lower TA and then adjusting pH back up afterwards. THAT does not work!
SO, I would have to say that they are just regurgitating back the same old 'industry myths' that refuse to die with no real understanding of pool water chemistry!

Here is the link to their 'Pool Chemistry page'. I suggest putting deep boots on before going there!
http://acsp.biz/page.php?64
 
you too waterbearer are one of the opinions that i value highly here. thanks for replying.


waterbear said:
I assume you have read this:
water-balance-tips-for-a-swg-t3663.html
I will not comment on the link you provided since it contains a lot of half truths and if you have nothing nice to say...

However, since carbonate alkalinity is the main factor in determining how fast the pH will rise from outgassing of CO2 then NOT correcting for CYA will work in your favor with a SWG since, if you keep your CYA at the recommended levels your TA will be lower than you think it is!
(Actually, the TA levels we recommend take all that into account as long as your CYA is also within the recommended range. Also, the usefulness of correcting TA for CYA has been debated in the industry for years and , except for calculating Saturation Index (which itself is of dubious value) the corrected TA is not a useful measurement at all.
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did that. i have my borates at 50ppm
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And still have that mondo-infestation, eh? I, for one, would like to see a picture of these little monsters. I'd like to know what it is.

I don't suppose there's any way that they could be burrowed in there, and they're balling up as they're coming out into the pool?
 
teppy said:
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Now, if i could just find someone, ANYONE to tell me why i am infested with bugs every morning.

teppy, it comes with the territory when you live in Louisiana :lol: JK. I used to live there many years ago and my parents and brothers still do
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waterbearer- i actually posted a link to the post that you wrote about CYA and a SWG. i did not get a reply yet. here is the link in case your interested in defending your post if it gets a response.Its been hours and nothing yet. the people at garden web are great for pool construction, but really they don't know diddly about pool maintenance. i loved hanging out there when my pool was being built and still do just to look at the pools being built. but, i learned about this site early on when it came to my pool water.

waterbear said:
I assume you have read this:
water-balance-tips-for-a-swg-t3663.html
I will not comment on the link you provided since it contains a lot of half truths and if you have nothing nice to say...

However, since carbonate alkalinity is the main factor in determining how fast the pH will rise from outgassing of CO2 then NOT correcting for CYA will work in your favor with a SWG since, if you keep your CYA at the recommended levels your TA will be lower than you think it is!
(Actually, the TA levels we recommend take all that into account as long as your CYA is also within the recommended range. Also, the usefulness of correcting TA for CYA has been debated in the industry for years and , except for calculating Saturation Index (which itself is of dubious value) the corrected TA is not a useful measurement at all.

heres the link:

http://ths.gardenweb.com/forums/load/po ... 004.html?9


Edit: did a bit more checking on that site and they don't seem to know the difference between magnesium and manganese (manganese causes purple stains) and they recommend 'slugging acid' to lower TA and then adjusting pH back up afterwards. THAT does not work!
SO, I would have to say that they are just regurgitating back the same old 'industry myths' that refuse to die with no real understanding of pool water chemistry!

Here is the link to their 'Pool Chemistry page'. I suggest putting deep boots on before going there!
http://acsp.biz/page.php?64
Click to expand...
 
So, I'm doomed?? i'm going to go out a try to photograph some of these clusters. i'm telling you, most people would not believe the extent of what i'm talking about. my husband told me yesterday that my mother in laws pool does not have bugs like that in hers and she must know what she's doing. Thats a load of Crud, she hauls water samples in the pool store when hers turns green. then she adds so much that the water smokes. yeah, it looks dangerous. either she has no bugs because she fries them or her water is so nasty that they don't want to go in.


orthofish said:
teppy said:
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Now, if i could just find someone, ANYONE to tell me why i am infested with bugs every morning.

teppy, it comes with the territory when you live in Louisiana :lol: JK. I used to live there many years ago and my parents and brothers still do
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