Best practices when using a Chlorinator?

bmccarty

Bronze Supporter
Mar 8, 2017
41
Sonoma, CA
#1
Hi all, I'm a new pool owner. I've been reading all the getting started notes and the Pool School and chemistry posts and I think I understand the TFP approach to water treatment using bleach/chlorine and not using chlorinators as the primary means of sanitizing due to CYA buildup.

The TFP approach makes complete sense to me but I'm not sure that I'm ready to take on all the other responsibilities of pool maintenance (filter cleaning, equipment monitoring etc) just yet. So in the meantime I'm looking at using a pool cleaning/maintenance service.

From talking to them it seems they have different approaches to sanitizing the water. One said he'd use Trichlor pucks but then also "shock" the pool once a week. I assume this is an approach to deal (somewhat) with the CYA build up; that the shocking helps compensate for the CYA buildup.

I dutifully asked about CYA build up and he said that typically it will build up over the summer but then get diluted in the winter with the rain. I live in Northern California and we typically get a lot of rain every winter.

So my question is, IF one is using a chlorinator what would be "best practices" for the overall approach to treatment? I have a Rainbow Model 300 Chlorine off-line feeder.

Thanks,
Brad
 

ping

TFP Expert
LifeTime Supporter
Jun 24, 2011
2,939
Long Beach, CA
#2
The best practice is to test the water frequently with one of the recommended test kits and adjust only what is needed to maintain proper balance.

Accurate water test results are the key to simple pool care. Having a TF-100 or Taylor K-2006 test kit is an absolute need for pool care.

If you are sticking with a service you will want to follow what they do as that is what they are familiar with. That said, there are many ways to care for a pool and each method will require that you follow that method and not mix two or more methods.

Keep reading in Pool School and the countless threads in the forum and you will learn that pool care is very simple once you understand the basics.
 
Mar 23, 2017
15
Edmond, OK
#3
Welcome to the wonderful world of pool ownership!

While I'm new here on this site as well, this is my 5th year of taking care of my pool. I too have a Rainbow auto chlorinator the only difference being mine is plumbed in-line with the output of the filter. I am switching this year to the TFP method just because I got so sick of using pucks only to find that even with what my tests considered to be proper levels of free chlorine, I was still brushing algae every 2 to 3 days due to the constant increase in CYA and the FC losing its effectiveness.

"Best Practices" IMO, with an auto-feeder, is to only add as much chlorinated water back to the pool as necessary to keep algae at bay and whatever you do, try not to shock it too much. The goal will be for you to make it the whole season without having to do a partial drain on the pool. Start the chlorine off as low as possible so you can keep increasing it as your CYA level rises while the chlorine maintains effectiveness. If you start out too high, you risk the highest output of your auto-chlorinator not being able to keep algae at bay in which you'll be in the situation I was in last year when my CYA was nearing 100ppm and even with the dial set to maximum chlorine, I still was getting algae.
 

pabeader

LifeTime Supporter
TFP Guide
May 14, 2015
4,349
Cartersville Ga
#4
One of our expert members did an example of trichlor (puck) use over time. It goes something like this.

If you start at 0 FC and 0 CYA at the beginning of the season and assume an average FC loss of 3ppm per day, here is what you get:
Every day you add enough trichlor (pucks) to get back to 3 ppm, you also add 1.8ppm CYA
Day 1 FC 3 CYA 1.8
Day 2 FC 3 CYA 3.6
Day 3 FC 3 CYA 7.2

On and on until
Day 22 FC 3 CYA 39.6

At this point you are at the absolute minimum FC you should have for the CYA level you are at. Algae is probably forming and the pool is getting cloudy.

If you continue with this trend

Day 55 FC 3 CYA 99

This is as far as the CYA test goes, so now you have to drain a significant portion of pool water to get the CYA back down to a manageable level.

This example doesn't take into account all the CYA you will add each time you use a powdered shock to try to clear up the algae that will be forming.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,388
Sebring, Florida
#5
You can use pucks but you must use a test kit as well. Please get one of the suggested kits we recommend so you can manage your FC and CYA correctly.
 

DeanP66

Well-known member
Mar 26, 2014
702
San Jose, CA
#6
One of our expert members did an example of trichlor (puck) use over time. It goes something like this.

If you start at 0 FC and 0 CYA at the beginning of the season and assume an average FC loss of 3ppm per day, here is what you get:
Every day you add enough trichlor (pucks) to get back to 3 ppm, you also add 1.8ppm CYA
Day 1 FC 3 CYA 1.8
Day 2 FC 3 CYA 3.6
Day 3 FC 3 CYA 7.2

On and on until
Day 22 FC 3 CYA 39.6

At this point you are at the absolute minimum FC you should have for the CYA level you are at. Algae is probably forming and the pool is getting cloudy.

If you continue with this trend

Day 55 FC 3 CYA 99

This is as far as the CYA test goes, so now you have to drain a significant portion of pool water to get the CYA back down to a manageable level.

This example doesn't take into account all the CYA you will add each time you use a powdered shock to try to clear up the algae that will be forming.
So, in less than two months, CYA is already off the chart and now you're stuck with either emptying water and refilling or keeping your FC at a very high level. JUST SAY NO to pucks, and only use them in an emergency like you're going out of town for a couple weeks or something like that.