Always low chlorine

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,005
Bedford, TX
Terry,

I find that a ladies knee-high stocking works best for adding CYA. It seems to dissolve faster, and the open end of the stocking acts like a string to hang the stocking in front of a return..
I fill the end of the stocking with CYA and tie a knot into the open end.

I have a 1 x4 about 3 feet long that has a notch in one end and an old pool chemical bucket that it filled with water. I set the board over the top of a return and then drop the knee-high full of CYA, through the notch and into the water, I can then adjust it up and down to be in front of a return. I put the bucket of water on the board and over the knot, which holds the knee-high and board in place...

I suggest that you initially shoot for a high FC than you want and then slowly bring it down by adjust the SWCG's output or pump run time.. It is very easy to adjust down, and much harder to adjust up. I always recommend starting high... In your case I would target 8 ppm to start with..

Thanks,

Jim R.
 

BTERRY1

Active member
Jul 27, 2019
27
San Diego
Terry,

I find that a ladies knee-high stocking works best for adding CYA. It seems to dissolve faster, and the open end of the stocking acts like a string to hang the stocking in front of a return..
I fill the end of the stocking with CYA and tie a knot into the open end.

I have a 1 x4 about 3 feet long that has a notch in one end and an old pool chemical bucket that it filled with water. I set the board over the top of a return and then drop the knee-high full of CYA, through the notch and into the water, I can then adjust it up and down to be in front of a return. I put the bucket of water on the board and over the knot, which holds the knee-high and board in place...

I suggest that you initially shoot for a high FC than you want and then slowly bring it down by adjust the SWCG's output or pump run time.. It is very easy to adjust down, and much harder to adjust up. I always recommend starting high... In your case I would target 8 ppm to start with..

Thanks,

Jim R.
Thanks. About how long to bring the CYA up in your experience?
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,005
Bedford, TX
Thanks. About how long to bring the CYA up in your experience?
Terry,

For me the CYA will dissolve in day or less... I squeeze the knee-high a few times a day... It takes a couple of days to show up in my tests..

I suggest that you only add half of what you think you need, and then test to make sure that the level is up to what you expected. If that works, then add more...

Jim R.
 

BTERRY1

Active member
Jul 27, 2019
27
San Diego
Update on progress. Here are my current readings after SLAM and getting the CYA dialed in. I tested and then took a sample to Leslie’s pool supplies to validate. I’ll list bothering below

My test
FC 4
CH 420
CYA 70
TA 90
PH 7.7

Leslie’s pool supplies
FC 2 he said he rounded down
Salt 2900. I need to test. I was 3500 a few weeks ago
CH same
CYA 60
PH same
Phosphate 2500

I don’t have a phosphate test. From this site though not to worry. Correct?

CH from site seems acceptable. They want me to drain some pool water. They say max 400.

So my first 2 questions. Worry about phosphate and CH?

My chlorine is barley keeping up at 80% generating setting. Normal? No overnight drops.

Lastly, what is more effective. Pump running peak sun times so generator can keep up with sun evaporated chlorine? Or run when dark to boost levels and then sun remove chlorine during the day.

Thanks y’all.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,005
Bedford, TX
Terry,

I never listen to anything a pool store has to say.. :mrgreen:

With your SWCG set at 80%, how long are you running your pump?

It does not really matter when you run, day or night, either way, you have to generate enough FC to last until you start generating more..

Jim R.
 

BTERRY1

Active member
Jul 27, 2019
27
San Diego
Terry,

I never listen to anything a pool store has to say.. :mrgreen:

With your SWCG set at 80%, how long are you running your pump?

It does not really matter when you run, day or night, either way, you have to generate enough FC to last until you start generating more..

Jim R.
2 hours at 3150 rpm and 6 hours at 2200.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,005
Bedford, TX
Terry,

Please go back and read my post #6..

You are running 8 hours at 80% which is only going to make 2.6 ppm of FC per day...

The SWCG only makes chlorine when the pump is running..

You have to adjust the pump run time and SWCG's output to generate at least as much chlorine as your pool is using.

If the pool uses more chlorine than your SWCG can produce, you have to increase your run time, and or, increase the output %..

Please let me know if this does not make sense...

Thanks,

Jim R.
 

BTERRY1

Active member
Jul 27, 2019
27
San Diego
Terry,

If you have any algae you can see, that means you have plenty of algae you can't see.. Any chlorine that your cell produces will get consumed by the algae..

Your cell, in your pool, should produce .41 ppm of FC per hour.. if run at 100% output.. So, in 8 hours it can only produce 3.3 ppm of FC.

Most pools in the summer use 2 to 4 ppm a day with the average being 3 ppm.. So unless you are running at 100%, your cell will have a hard time keeping up..

Logic says, that either the cell is not working, or something in the water is consuming the chlorine.. Since you have, or have recently had, some algae, that would be the first thing to test.

I suggest that you perform an Overnight Chlorine Loss Test (OCLT).. This is how.. Overnight Chlorine Loss Test

Basically, after sundown, use Liquid Chlorine and bring your FC up to above 8 or so.. Then get your rear out of bed before sunrise, and test again.. :) If you lose more than 1 ppm of FC then it means algae is consuming your FC. The only problem with this test is that you need to use a pretty accurate test kit.

Try that and let us know how it works out.

Thanks,

Jim R.
I went back and reread post 6. So I either need to let it run as is at 100 percent or increase the run time over what I am doing. I think I’d prefer 100 vs more electricity 👍. Unless not wise to run at max.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,005
Bedford, TX
Terry,

The cell does not care if you run it at 10% or 100%...

A CYA of 60 is fine... a CYA of 70 is better and you will use less FC..

Thanks,

Jim R.
 

Teald024

TFP Guide
Also, any concern with my CA numbers
Are you referring to CH (calcium hardness)?
You will be fine with a CH of 420, just keep pH on the lower side around 7.5 or 7.6.
When you get a chance, run a CH test on the water that you use to fill the pool. Let us know and we can advise if any alternate advice is needed.
Do you have a way of collecting rain water or funneling it into the pool instead of filling from a hose? This can help reduce or stop the rise of CH.
 

BTERRY1

Active member
Jul 27, 2019
27
San Diego
Oops yes. CH. at 420 I was worried about scaling. Tap water is only 40ppm.

I’ll adjust run time to keep chlorine up and monitor PH closely.

On average, how often are people having to add acid to reduce PH?