4 test results. Need a little advice.

[wkusae31]

Here are my test results after the second round of CYA addition. TF100 test kit.

On dates 5.19 and 5.26, these are the 4th days after I put the CYA sock into the pool (they dissolved within a day). Also, around 5.21.15, I turned my pump/heater on for 8 hours a day, running at 50% on SWG. Previously, the pool store had me set this to 24/7 at 50% SWG, but from TFP, you guys told me that running my pump 24/7 was too much so I scaled back to running 8 hours a day from around 10 am - 6 pm. I did a backwash before I tested on 5.22. My numbers are below.

Date 5.13 5.19 5.22 5.26
Salt 3600 3200 3200 2800-3200
FC 7.5 7 7.5 8
CC 0.5 0 0 NA
TC 8 7 7.5 NA
CH ~175 150-250 N/A 150
TA 70 80 70 80
CYA 0-20 ~35 ~35 ~45
pH 7.5 7.5 7.5 7.5

Based on "Water Balance for SWGs", I am within the normal range for most of these; however, I am still trying to get my CYA levels up to where it needs to be. I think I will have to do a 3rd round of CYA sock to get it around 70. Here are some questions:

1. Should I be concerned that my FC is getting a little higher at 8 ppm? I guess it would be normal since my Shock FC is also rising?
2. I'm pretty sure my salt test came in at 2800 today, but I did another test and it came in at 3200. Should I be concerned that my salt level is dropping? Is this due to running my SWG less and that I should turn my SWG from 50% to around 65% since I'm only running 8 hours a day compared to 24/7?
3. I'm incrementing my CYA about 20-25 each week so that I do not overshoot my goal.

What do you guys think? Thanks for all the help.

 

[Azgirl71]

1. You are correct your FC will be at a higher level as your CYA increased you have to increase FC. However in your case at 8FC and CYA 45, I would turn the SWG lower.

2. How are you testing your salt level?

3. Slowly raising CYA is good.

 

[wkusae31]

1. You are correct your FC will be at a higher level as your CYA increased you have to increase FC. However in your case at 8FC and CYA 45, I would turn the SWG lower.

2. How are you testing your salt level?

3. Slowly raising CYA is good.

Thanks for your response.

I am testing my salt with Taylor Salt Test kit that came with my TF-100. If I turn down my SWG to get the FC lower, wouldn't that lower my salt level?

 

[Divin Dave]

Hi Wk,
Your SWG is providing chlorine to the pool, so the FC is a result of your %output + run time.
It takes a bit of trial and error to get it just right. You are a few ppm higher than recommended right now, but is fine and perfectly safe. There is not need to have any concern about this.

As Azgirl asked, how did you measure the salt level? If you used strips, their accuracy is someowhat suspect to the tune of maybe 400 or 500 ppm. The Taylor K1766 titration test is a bit more accurate to about 200 ppm. If you took that reading from your SWG readout, then consider it accurate to 200 ppm.

Your FC target as you know is dependent upon the CYA. You should aim for 11.5% (so 45*.115=5.17) But never let the FC get below 7.5% of the CYA.

FC is good enough until you get it dialed in
CC is good
TC is good
TA is good
pH is good
CH is not applicable for vinyl pool. Just dont let it get way high, like +500

You're doing good man, just raise your CYA up a bit and adjust your SWG or runtime to compensate as needed.

hope this helps!

Here are my test results after the second round of CYA addition. TF100 test kit.

On dates 5.19 and 5.26, these are the 4th days after I put the CYA sock into the pool (they dissolved within a day). Also, around 5.21.15, I turned my pump/heater on for 8 hours a day, running at 50% on SWG. Previously, the pool store had me set this to 24/7 at 50% SWG, but from TFP, you guys told me that running my pump 24/7 was too much so I scaled back to running 8 hours a day from around 10 am - 6 pm. I did a backwash before I tested on 5.22. My numbers are below.

Date 5.13 5.19 5.22 5.26
Salt 3600 3200 3200 2800-3200
FC 7.5 7 7.5 8
CC 0.5 0 0 NA
TC 8 7 7.5 NA
CH ~175 150-250 N/A 150
TA 70 80 70 80
CYA 0-20 ~35 ~35 ~45
pH 7.5 7.5 7.5 7.5

Based on "Water Balance for SWGs", I am within the normal range for most of these; however, I am still trying to get my CYA levels up to where it needs to be. I think I will have to do a 3rd round of CYA sock to get it around 70. Here are some questions:

1. Should I be concerned that my FC is getting a little higher at 8 ppm? I guess it would be normal since my Shock FC is also rising?
2. I'm pretty sure my salt test came in at 2800 today, but I did another test and it came in at 3200. Should I be concerned that my salt level is dropping? No. The only way to loose salt is through dilution. It doesnt get 'Used Up'. Bottom line, is if you dont have a Low Salt Alarm on your SWG system and its generating chlorine, then the salt level is good. Is this due to running my SWG less and that I should turn my SWG from 50% to around 65% since I'm only running 8 hours a day compared to 24/7?
3. I'm incrementing my CYA about 20-25 each week so that I do not overshoot my goal.

What do you guys think? Thanks for all the help.

 

[Divin Dave]

Nope, it doesnt.

turning down the SWG will only lower the FC.
No matter how low or high you want your FC to be, the SWG needs x amount of salt to generate chlorine. There is no correlation between the FC output and the salt level.

Most SWG's recommend an optimum level of ~3400, but will generate chlorine even if you are a bit high or low from there.
The 3400 is enough to allow for a bit of dilution through backwash, rain overflow, splashout etc, and not have to add salt all the time.

Thanks for your response.

I am testing my salt with Taylor Salt Test kit that came with my TF-100. If I turn down my SWG to get the FC lower, wouldn't that lower my salt level?

 

[wkusae31]

Nope, it doesnt.

turning down the SWG will only lower the FC.
No matter how low or high you want your FC to be, the SWG needs x amount of salt to generate chlorine. There is no correlation between the FC output and the salt level.

Most SWG's recommend an optimum level of ~3400, but will generate chlorine even if you are a bit high or low from there.
The 3400 is enough to allow for a bit of dilution through backwash, rain overflow, splashout etc, and not have to add salt all the time.

Divin Dave: Thanks for the response. I guess I've been only at the pool ownership business for a month and I think I know enough to be confused, at times. I guess that I falsely assumed that the SWG generated number correlated with the Salt PPM, even though I test my Salt with the Taylor Kit. So when you're saying that "Most SWG's recommend an optimum level of ~3400...", you mean that my salt number from my Taylor Salt Test needs to be around ~3400, right? It appears from my 4 tests that my salt content is slowly decreasing. I'm assuming that I should dump some salt in the deep end to raise my salt level another 200-300 PPM? If so, can I do the salt addition with my on-going CYA addition?

 

[pooldv]

You can add salt while adding CYA. But, if your SWG is happy and making chorine and lot giving a low salt error there is no reason to add salt.