Initial Pool Chemistry

[kaymaza]

Hello everyone,

I just recently received my TFT test kit. I have a brand new SWG pool and spa with plaster. I'm based out of the Las Vegas area and we recently had some storms come in. Here are my pool chemistry results from this evening (1/17/23):

1/17/23
pH 7.8 - 8.2 (I've been getting varying readings with my pH measuring device. Using the basic OTO test kit it appears that the pH is around 8.2)
Free Chlorine 0.5 ppm
Combined chloramines 0.5 ppm
Total Chlorine 1 ppm
TA 130 ppm
Ca Hardness 170 ppm
CYA 30
Salt 0 - 1000 ppm

How should I go about addressing this? Should I tackle the high pH first? I appreciate any input. Thanks!

 

[mknauss]

Welcome to the forum

You need chlorine. Now. Get the FC to target range based on FC/CYA Levels

What is your TA. If fresh fill, it should be around 130 ppm. Use that number in PoolMath to get how much acid to add to lower pH to 7.6.

 

[kaymaza]

Welcome to the forum

You need chlorine. Now. Get the FC to target range based on FC/CYA Levels

What is your TA. If fresh fill, it should be around 130 ppm. Use that number in PoolMath to get how much acid to add to lower pH to 7.6.

Spot on. TA was 130 ppm. Based on the pool math app w/ a 15K gallon pool & spa SWG w/ plaster, I'll be adding 78 oz of liquid bleach, 26 oz of 31.45% 20° Baume and 90 oz of stabilizer. Will give 10 mins in between added each of the chemicals. Does that sound about right?

Also since I have plaster, my CH levels were 170. Pool math app suggests 18 lbs of Calicum Chrloide to reach a target of 300. That sounds a bit much. Should I spread it out and do like 6 lbs per week?

I've attached some photos providing a general visual inspection of my pool and spa. Thankfully it looks like there doesn't seem to be any algae and appears mostly clear. Thank you thank you again for the suggestions!

 

[kaymaza]

Welcome to the forum

You need chlorine. Now. Get the FC to target range based on FC/CYA Levels

What is your TA. If fresh fill, it should be around 130 ppm. Use that number in PoolMath to get how much acid to add to lower pH to 7.6.

Actually upon reviewing the FC/CYA chart, how would I go about adding the chlorine when my CYA levels are 30?

 

[mknauss]

Add chlorine to get to target range FC. I would not add CYA yet as it is winter. Start adding that in early March. I also would not add calcium. Your fill water CH is 250 ppm (test the fill water CH and TA). With evaporation your CH level will go up quickly as you add fill water. Unless you are using softened water for fill water.

 

[kaymaza]

Add chlorine to get to target range FC. I would not add CYA yet as it is winter. Start adding that in early March. I also would not add calcium. Your fill water CH is 250 ppm (test the fill water CH and TA). With evaporation your CH level will go up quickly as you add fill water. Unless you are using softened water for fill water.

Got it thanks. I do have a water softener but per the pool builder, they are separate and so the fill water should not be softened.

 

[kaymaza]

When I review that FC/CYA chart for the salt water generator, I'm not sure what the target FC should be then since my CYA is currently 30 and the lowest level provided on that chart is 60 for a SWG. What should my target FC be?

 

[mknauss]

You really want to use softened water for make up fill water. Or plan to drain and refill the pool every 18-24 months.

 

[mknauss]

Fo

When I review that FC/CYA chart for the salt water generator, I'm not sure what the target FC should be then since my CYA is currently 30 and the lowest level provided on that chart is 60 for a SWG. What should my target FC be?

Follow the liquid chlorine chart for now. Your SWCG will not generate with cold water temperatures.

 

[kaymaza]

You really want to use softened water for make up fill water. Or plan to drain and refill the pool every 18-24 months.

Can you explain why I would need to drain and refill the pool every 18-24 months? I spoke to my pool builder about using softened water for make up fill water and he told it wasn't necessary since I have a SWG pool . Thanks again.

 

[mknauss]

Your pool water will evaporate. About two pool volumes a year. The CH in the water stays behind. Thus, the CH adds up and once you get to about 800 ppm , it is no longer viable to manage the CSI to prevent scale build up and you must drain and refill the pool.

 

[kaymaza]

Your pool water will evaporate. About two pool volumes a year. The CH in the water stays behind. Thus, the CH adds up and once you get to about 800 ppm , it is no longer viable to manage the CSI to prevent scale build up and you must drain and refill the pool.

Just so I understand, the reason not to be concerned about the low CH level that I'm getting (170 ppm) and potentially damaging the plaster along w/ scaling, is it because the CSI I'm getting is 0.2 which is in an appropriate range? Thank you so much again for all your answers.

 

[mknauss]

The low CH (which is a bit suspect as your fill water CH should be about 250 ppm) will rise quite quickly in the next few months.

Does the pool builder want to add calcium?

 

[kaymaza]

The low CH (which is a bit suspect as your fill water CH should be about 250 ppm) will rise quite quickly in the next few months.

Does the pool builder want to add calcium?

No plans to add calcium just salt salt in the week.

 

[mknauss]

I would not add salt until your pool water temperature is consistently above 55f.

 

[kaymaza]

I would not add salt until your pool water temperature is consistently above 55f.

I checked the pool chemistry this evening and just wanted to give you an update.

1/19/23
pH 7.5. Although using the basic OTO test kit, the range of the pH is 7.8 - 8.2. May need to recalibrate my pH meter.
Free Chlorine 6.5 ppm
Combined Chloramines 0
Total Chlorine 6.5 ppm
TA 140 ppm
CYA 30
Salt 0 - 1000 ppm
Pool water 44 deg F

Any other suggestions at this point? Pool looks clear otherwise. As always, thank you for your advice!

 

[PoolStored]

1/19/23
pH 7.5. Although using the basic OTO test kit, the range of the pH is 7.8 - 8.2. May need to recalibrate my pH meter.
Free Chlorine 6.5 ppm
Combined Chloramines 0
Total Chlorine 6.5 ppm
TA 140 ppm
CYA 30
Salt 0 - 1000 ppm
Pool water 44 deg F

Any other suggestions at this point?

What was your CH?
What is your specific concern?
What does "Salt 0 - 1000 ppm" mean?
Do you have a K-1766 salt test? Or...how are you testing salt?

 

[kaymaza]

What was your CH?
What is your specific concern?
What does "Salt 0 - 1000 ppm" mean?
Do you have a K-1766 salt test? Or...how are you testing salt?

Didn't check the CH. I last checked it 2 days ago and it was 170 ppm. I have the Taylor Test Strips that tests for NaCl and glancing at the results it looks like it's about 0 - 1000 ppm for NaCl.

My only concern is that for the free chlorine, it went from 0.5 to 6.5 ppm. It was a lot higher than the ideal target free chlorine (3 ppm) that I originally had on the Pool Math app. Just wanted to see if that is concern with the free chlorine jumping that high. Also, not sure what steps I need to take next or if I can space out the pool chemistry testing.

 

[AlexPowell]

It's a common theme amongst beginners, which included myself, that won't really understand the importance of the TA and CH values. This is largely because of what is recommended in PoolMath.

PoolMath shows that CH should be between 250-650 in a plaster pool with SWCG. It's not obvious for newcomers that this will rise to be in range naturally and doesn't need intervention. Perhaps this can be added to Pool School?

 

[PoolStored]

Didn't check the CH. I last checked it 2 days ago and it was 170 ppm. I have the Taylor Test Strips that tests for NaCl and glancing at the results it looks like it's about 0 - 1000 ppm for NaCl.

My only concern is that for the free chlorine, it went from 0.5 to 6.5 ppm. It was a lot higher than the ideal target free chlorine (3 ppm) that I originally had on the Pool Math app. Just wanted to see if that is concern with the free chlorine jumping that high. Also, not sure what steps I need to take next or if I can space out the pool chemistry testing.

So, let's start with FC. You are in the off season, so no big deal. But, CYA of 30 is really low for SWG. You are ok for now, but in the spring, get ready to raise it to 60-70. FC up to 12, with CYA of 30 is completely safe to swim and safe for your pool. No worries.

On the "ideal" FC, for SWG and CYA of 70 (a nice target for you in henderson), you can easily run your pool 6-9FC with no worries. It is better to error on the high side as this will absorb high FC demand days (sun and swimmers). Running on the low end of FC and getting to miminums is LAVA. Running at 6-9, you will never notice, is completely safe.