Pucks VS. chlorine usage conundrum

woodyp

Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
10,589
East Texas
Before y'all get all testy, I'm a liquid bleach kinda guy thanks to all of you!

My question concerns people who constantly use pucks for their chlorine levels. I know the pucks constantly raise the CYA levels in your pool. My understanding is that the only downside of using pucks is that the more CYA they add---------the more chlorine demand on the pool should be. So when CYA reaches levels of say 120 to 150 or even higher, why don't I see any stories here saying like,........"When I started using pucks it only took one a day but now my CYA level is so high that I have to use 10 a day to maintain a safe chlorine level." (which raises the cya level even more).
How could you possibly maintain good chlorine levels at that high of a cya content, and why don't I see anyone complaining about it? Is the additional chlorine requirement for a higher level of cya content the only downside to higher cya levels?

Just curious and hope it helps others here as well that are considering the BBB method. Thanks folks!
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
22,069
San Dimas, CA (LA County)
They go to the pool store, which sells them a product called "shock," which they recommend you use weekly. :shock: So the pool gets a massive dose of chlorine and calcium. Algae dies. Pool gets saturated with yet another chemical compound. Eventually they recommend a drain and refill. Oh, and you'll need this startup kit for the fresh fill water....
 

poolgirl22

Platinum Supporter
LifeTime Supporter
Apr 14, 2010
595
Stephens City, VA
My 2 cents is that they really don't know what is happening. I used pucks exclusively up till this year. Never knew any different. I just thought what was happening was the norm and we adjust accordingly.
The typical pattern is early in the season I had the chlorinator on medium or low and pump ran 8-12 hrs a day. Then as the the season continued the chlorinator went up to high, I filled the pucks more often, I had to shock more often, and the pump ended up running 24 hrs a day. I posed the question to the pool store as to why I was running through tablets so fast and they just said 'oh it's cuz its more hot and humid.' Now I know it's not so much that as it is my CYA was soaring because of course I had to add stabilizer in the beginning of the year as well. I vividly remember having CYA numbers well over 100 toward the end of the year.

I've talked to some folks who use tablets from the get go at opening, don't add CYA separately, and don't have too much trouble or are fine with throwing the shock bags in once a week and not worrying about it. Great...but for me, it just wasn't working.

To me personally, the proof is in what's in my back yard.
 

woodyp

Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
10,589
East Texas
I haven't bought any (haven't needed any) so I forgot all about using shock to jump those chlorine numbers back up into the stratosphere. Good answers folks. Thanks. Just had a neighbor down the street put in a doughboy 12x24 half buried a month after I had my AGP done. Told her all about this site and wrote it down for her. Then she showed me her standard pool chemical rack with around $250.00 of just "setup" stuff. They didn't even give her a cheapie water testing kit! Already have her putting algaecide in the thing right off the bat. Got her attention when I asked her is she had any algae coming out of the taps in the house. I'll work on her! A couple of my neighbors who have had pools in the past marvel how clear and clean mine is with just clorox and muriatic acid on hand. Thanks TFP!
 

Jimbolo

LifeTime Supporter
Feb 3, 2010
56
I have used pucks for the two months since I've owned the home/pool. My CYA and FC are higher than the test kit will measure, but I still get the beginnings of algae if I don't shock.

I have a cartridge filter, so I don't back wash and replace water ever. There is only evaporation and replacement, which makes the CYA concentration even more extreme (not to mention off-the-chart calcium). I'm going to dump 2/3 of my water next week, refill, and get off the pucks.

So when folks say that high CYA requires more chlorine to get the same sanitation, I think (at least it seems to be in my experience) that you still have high FC readings, but you don't get the same cleaning at the same level. Hence the presence of algae in my pool even though I have very high FC.

Jim.
 

woodyp

Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
10,589
East Texas
Somebody needs to design us a logo like the "No Smoking" signs....................a puck in a red circle with a diagonal red line through it!
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,859
Sebring, Florida
You know, I sorta like that idea of some sort of logo that we could maybe use on the Home Page of TFP. It might be a little difficult to replicate the pucks so they would be instantly recognizable.....What about a big picture of Clorox?

Any other thoughts?

(Hey, bamapool)
 

Isaac-1

TFP Expert
LifeTime Supporter
May 10, 2010
6,711
SW Louisiana
I think trichlor pucks are a growing problem with more and more people are either installing cartridge filters that don't need backwashing, or have some other form or water restriction so they don't drain and refill as much as people in the past. Combine this with other things that extend the traditional swim season (solar blankets, solar heaters, etc) and we are getting away from what was the fairly common, start in the spring with a mostly fresh water fill, add enough stabilizer to get it into the suggested CYA range, add pucks all summer slowly raising the CYA to insane levels, doing weekly preventive "shocks" that get less and less effective as the CYA raises, finally ending in a crisis around the time the swim season ends. Thereby justifying the drain and refill prior to starting the cycle all over again the next spring.

Ike
 

BamaPool

Active member
Jun 8, 2010
38
South Alabama
OK Give me a couple of days and i will have some stickers made like the one in richards post...then i will just need a size if it is small the pucks prolly will not show though...
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
22,069
San Dimas, CA (LA County)
BamaPool said:
OK Give me a couple of days and i will have some stickers made like the one in richards post...then i will just need a size if it is small the pucks prolly will not show though...
Wait a few days, and I'll make a better looking larger drawing. That was a rush job. And you may get other submissions, too!
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,083
San Rafael, CA USA
Jimbolo said:
I have used pucks for the two months since I've owned the home/pool. My CYA and FC are higher than the test kit will measure, but I still get the beginnings of algae if I don't shock.

I have a cartridge filter, so I don't back wash and replace water ever. There is only evaporation and replacement, which makes the CYA concentration even more extreme (not to mention off-the-chart calcium). I'm going to dump 2/3 of my water next week, refill, and get off the pucks.

So when folks say that high CYA requires more chlorine to get the same sanitation, I think (at least it seems to be in my experience) that you still have high FC readings, but you don't get the same cleaning at the same level. Hence the presence of algae in my pool even though I have very high FC.

Jim.
Jim,

From your post here your FC level is above 5 ppm (the limit of the K-2005 test) and the CYA well above 100 ppm, probably around 200 ppm or more. So there is no wonder that you still have algae. If the CYA were at 200 ppm and if your pool was rich in algal nutrients, then the any chlorine level below around 15 ppm FC and certainly below 9 ppm FC (which is still higher than the 5 ppm your test can read) is likely to have algae grow faster than chlorine can kill it.

I don't understand how you got your CYA level to 200 ppm in two months since pucks alone would not do that. Did you add a lot of stabilizer/conditioner when you first filled the pool? Did you inherit this pool (say, by buying this house)? Have you been shocking with something like Dichlor powder?

The fact is that you do get the same algae prevention level when you maintain the appropriate FC/CYA ratio. In your situation, you simply are not doing so, mostly because you can't measure the FC accurately since it's just "above 5 ppm" in your case, though you could try diluting with distilled or filtered water to get a better FC reading (or better yet, buy a FAS-DPD chlorine test kit such as the one here at tftestkits.net). Also, you need to get way ahead of already-existing algae growth by shocking, but that is impractical with your high CYA level.

It'll be a good move to do the partial drain/refill and get off the pucks and start using chlorinating liquid or bleach.

My own experience with pucks was as others have described. All was fine for a while, but after 1-1/2 years, my CYA climbed from 30 ppm to around 150 ppm and I started to get a higher chlorine demand requiring more pucks. This was in spite of using PolyQuat 60 algaecide, but I was only adding it every other week. I was getting nascent algae growth even though it was not yet visible. Soon the water started to get dull and then cloudy before I gave up on the pool store and decided to figure out pool water chemistry, found The PoolForum, and the rest is history. Haven't had any such problems since switching to chlorinating liquid and maintaining an appropriate FC/CYA ratio.

Richard
 

Benoit Perron

New member
Jun 1, 2010
3
I currently have a CYA level of near zero (as per my cheap strip test but "confirmed" by tests at the pool store) and am using pucks in the hopes of raising it to an acceptable level. Since I have the blanket on very often I have to put the chlorinator on a low setting otherwise it's up to shock level in a week.

Would I be better off just putting stabilizer into the pool? How long would it take otherwise to raise the CYA using 2-3 pucks per week and periodic backwashes? (hopefully not in years!)

thanks!