Pool guy told me using bleach to chlorinate my pool will eat up the plaster faster???

Morketh

Well-known member
Oct 17, 2018
63
KATY/TX
#1
I just got a pentair variable speed pump installed and I have a chlorinator. Well if I decide to run the pump at 1850rpm or less he said the chlorinator is not going to work (which i was putting 3 inch chlorine tablets in).
I told him "oh thats no problem I read about how to treat my pool on trouble free pool and I will be using bleach as soon as I run out of tablets because tablets boost my CYA levels and I cant bring them down unless I do partial drains or aerate the water"
And his response was that I might not want to do that because the bleach will eat away at the plaster much faster than the chlorine tablets.

I am going to take a wild guess and say he is full of it?

Secondly, does anyone know what speed your pump needs to be running at to make a chlorinator useful?
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,535
Bedford, TX
#2
Keith,

He is overflowing with it... Chlorine is chlorine, it just comes in different packages. Once it is in the water, it is the same chemical.

You have found another reason not to use 3" tabs... It makes you run your pump much faster than you need..

Most of the time, my pump runs at 1200 RPM, but I have a Saltwater Chlorine Generator.. It does not work when the water gets below 52 degrees and then I switch to Liquid Chlorine /Bleach. My speed stays the same..

Thanks,

Jim R.
 

an1vrsy

Bronze Supporter
Jul 10, 2018
57
Rancho Santa Margarita, CA
#3
The rpm's on the variable speed pump makes sense now. I went on a 7 day vacation and wanted to raise my CYA anyway which was hovering right around 30ppm. So, I dropped in 3 tabs (21 oz) which according to pool math would raise my CYA by 6.5ppm.

Eighteen days later, I finally took out the 3 tabs out because they weren't really dissolving, I let them dry out then I weighed them, 14 oz. I couldn't believe that only 7 oz had dissolved in 18 days but I chalked it up to the chlorinator was somehow broken. Oh well, TFP methods have proven to me it is better to use 12.5% chlorine anyway so nothing really lost.

Now, your post caused the light bulb to go off that the variable speed pump's rpm weren't high enough to force water through the chlorinator to dissolve the tabs. Question answered. Thanks @Morketh
 

Donldson

TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
3,288
NW Ohio
#4
Interesting, since plaster is negatively affected by acidic water and pucks are highly acidic I would say he has it bass ackwards. I guarantee more plaster is destroyed by misuse of pucks than by using bleach (I imagine some people who use bleach but not CYA do find their finish fades faster, but following TFPC will more likely extend the life of your finish overall).

An inline chlorinator should work to some extent regardless of the speed you run your pump, but the faster the water flows the faster the pucks will dissolve. There will be a point where the chlorine introduced won't match the chlorine being consumed, but that involves a lot of variables so there is no universal answer as to the minimum speed needed.
 

Morketh

Well-known member
Oct 17, 2018
63
KATY/TX
#5
The rpm's on the variable speed pump makes sense now. I went on a 7 day vacation and wanted to raise my CYA anyway which was hovering right around 30ppm. So, I dropped in 3 tabs (21 oz) which according to pool math would raise my CYA by 6.5ppm.

Eighteen days later, I finally took out the 3 tabs out because they weren't really dissolving, I let them dry out then I weighed them, 14 oz. I couldn't believe that only 7 oz had dissolved in 18 days but I chalked it up to the chlorinator was somehow broken. Oh well, TFP methods have proven to me it is better to use 12.5% chlorine anyway so nothing really lost.

Now, your post caused the light bulb to go off that the variable speed pump's rpm weren't high enough to force water through the chlorinator to dissolve the tabs. Question answered. Thanks @Morketh
lol I'm glad something I asked actually helped someone else :)
 

KDpoolguy

Bronze Supporter
Mar 5, 2017
302
Palm Desert, CA
#6
Great post dispelling rumors and conjecture. I will submit something I view as extremely pertinent: we’re all doing markedly positive things to our pools by managing them well and helping others learn appropriate ways to improve their pool maintenance skills!
The number of pools I see as swamps, drained (as in they gave up) semi-abandoned or somewhere in between!!! I have a neighbor who code enforcement was out endlessly to deal with his cesspool=dangerous breeding ground for mosquitoes. I literally took the dog on a walk, chlorine shock powder bag in hand, poked holes and all, and chucked it over his 7 foot cinder block wall into the pool (“nothin but net ;) and sent my drone over later to see if it made a difference.
My point being, managing a pool for the future enjoyment of family and friends and also just for the pure care of the life of the pool is an honorable thing to do, and just working at chem management is so much better than a cesspool-especially when I see how it affected my current pool’s old plaster, permanently stained by its days as a swamp, long before I got it. Working at good pool manners is so much better than total disregard for it. Amen!
 

x Wild Bill x

Well-known member
May 5, 2016
52
Rochester, MA
#7
Since everyone has already covered the main statement about liquid chlorine, I want to point out an error in your statement you made to the pool boy of "oh thats no problem I read about how to treat my pool on trouble free pool and I will be using bleach as soon as I run out of tablets because tablets boost my CYA levels and I cant bring them down unless I do partial drains or aerate the water"
Aerating the water will not reduce the CYA in your pool, it will only increase the PH of your water. The only way CYA can decrease is: through draining and water replacement or dilution, it is slowly consumed over time naturally and lastly in rare circumstances it is consumed by organisms and turned into ammonia which is not a good thing!
I am not trying to nit pic or call you at, I just wanted to inform you for your own knowledge. I would have hated for you to not realize it and in the future be aerating your water trying to lower CYA while only increasing you PH.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,535
Bedford, TX
#9
Dave,

Each pool is different, you just need to experiment to see where your flow switch comes on.. Then add 100 RPM, just to make sure, and that will be the lowest speed you can run and ensure your flow switch is closed.

Obviously, for me, 1200 RPM, always closes my flow switch..

I gave up listening to what my pool builder told me a long time ago. He basically knows what subs to call to have a pool built, and not much else... :cool:

Thanks,

Jim R.