New to the group and had a question about FC, CC, and TC

[TeamFreddy]

Need a little help... My understanding is FC+CC=TC

Having had a fresh built pool for one week and not having a pool since 2014 I have been using a combination of test strips, K2006, and LPS to make sure my testing with the K2006 is accurate or close. I have found FC with the test strips to be inaccurate and hard to get a precise number on CYA and TA with the strips. That is a given being that they are test strips.. so I take their results with a grain of salt.

I tested this morning with the K2006 kit as ive been working on lowering TA. A few hours later while running errands I stopped by the LPS and had them run a test one thing that stood out was TC and FC had such a huge variance. My understanding Is CC over .50 indicates a problem. According to the LPS Store results I would be over the .5 threshold and according to my Taylor kit I am within threshold. Having tested twice at home, once before and once after getting the same result both times I am questioning LPS FC and TC.

with that said is there anything I can do to prevent CC from passing the .5 threshold? I want to make sure I stay on top of it and not have a problem in my hands that could of been prevented.

** Also wanted to point out I am working on bringing TA within recommended threshold and will work on CH after.

	AM Test W/K2006	Local Pool Store	PM Retest
FC	5.8	5.14	5.8
CC	.2	Assuming CC = 1.42 (FC+CC=TC)	.2
TC	Assuming 6.0 (FC+CC=TC)	6.56	Assuming 6.0 (FC+CC=TC)
PH	7.8	7.8
TA	150	139
CH	N/A	128
CYA	~35	39

Thanks in advance and look forward to absorbing and being able to pass the knowledge.

 

[ajw22]

Toss the test trips in the trash and stay out of the LPS.

Both will simply give you confusion from their inaccurate results.

Trust your K-2006 testing.

All your numbers look good except for CH and I would not spend time forcing your TA down. Manage your pH and keep it in the mid 7's and your TA will come down over time. Unless you have high TA fill water in which case you will never win the battle.

Turn on CSI tracking in PoolMath and calculate your CSI.

Understand that the CSI is not applicable to new plaster finishes under 30 days old. It is actually necessary, to achieve a smooth and dense surface, to have about a +0.5 CSI during the first 30 days. This is because the plaster (cement paste) surface contains about 20% calcium hydroxide, which is somewhat soluble in balanced and slightly positive CSI water and can be dissolved away. The plaster surface needs to be "carbonated" before the CSI should be lowered to the acceptable and balanced range. And that generally is achieved during the first month under balanced water.

Get calcium chloride and raise your CH to 250-300, Your water needs some CH or it will pull it from the plaster.

What is the pH and CH of the fill water you will be using?

 

[TeamFreddy]

Toss the test trips in the trash and stay out of the LPS.

Both will simply give you confusion from their inaccurate results.

Trust your K-2006 testing.

All your numbers look good except for CH and I would not spend time forcing your TA down. Manage your pH and keep it in the mid 7's and your TA will come down over time. Unless you have high TA fill water in which case you will never win the battle.

Turn on CSI tracking in PoolMath and calculate your CSI.

Understand that the CSI is not applicable to new plaster finishes under 30 days old. It is actually necessary, to achieve a smooth and dense surface, to have about a +0.5 CSI during the first 30 days. This is because the plaster (cement paste) surface contains about 20% calcium hydroxide, which is somewhat soluble in balanced and slightly positive CSI water and can be dissolved away. The plaster surface needs to be "carbonated" before the CSI should be lowered to the acceptable and balanced range. And that generally is achieved during the first month under balanced water.

Get calcium chloride and raise your CH to 250-300, Your water needs some CH or it will pull it from the plaster.

What is the pH and CH of the fill water you will be using?

Thanks For the reply. I will toss the strips and stay away from LPS

I will continue to stay on top of PH and turn on CSI as suggested.

Calcium Chloride is ordered and will be here Monday which is when I planned on starting to Focus on bringing up CH.

Great question on what my source PH and CH is I will have to run a test and report back. I actually enjoy the testing part especially when I start seeing consistent numbers.

Once again thanks for the reply and look forward to learning more from everyone.

 

[mknauss]

Calcium Chloride is ordered and will be here Monday which is when I planned on starting to Focus on bringing up CH.

What is your water source? It is rare in Arizona to need to add calcium to a pool.

 

[ajw22]

Great question on what my source PH and CH is I will have to run a test and report back.

Test pH, TA, and CH of your fill water.

 

[TeamFreddy]

What is your water source? It is rare in Arizona to need to add calcium to a pool.

The water source is the hose bib... I wanna say its just City water. I will run a test later today to see what the source water levels are.

 

[mknauss]

I wanna say its just City water.

What City?

 

[TeamFreddy]

What City?

Goodyear.

 

[mknauss]

I believe you use nearly all Colorado River water. The CH of that is higher than 250ppm. No need to add calcium to this pool.
Will you be using that water for make up water due to evaporation?

Check the water quality report from the City or company that supplies your water. Look for Calcium, typically in Grains per Gallon. 16 gpg is equivalent to about 250 ppm CH.

 

[TeamFreddy]

I believe you use nearly all Colorado River water. The CH of that is higher than 250ppm. No need to add calcium to this pool.
Will you be using that water for make up water due to evaporation?

I believe you are right it should be coming from the Colorado River. I have an ATO that is plumed to the hose bib so yes all top off will come from the same source.

 

[mknauss]

I believe you are right it should be coming from the Colorado River. I have an ATO that is plumed to the hose bib so yes all top off will come from the same source.

OK -- then do NOT add any calcium.
Your CH will nearly triple in a year to 18 months. Then you will have to drain the entire pool and start over.

If you have a whole house water softener, I suggest you see if you can plumb your make up water to come from the softener.

Myself and some others use RV water softeners just for our pool so we do not have to drain every 18 months, give or take.

 

[TeamFreddy]

OK -- then do NOT add any calcium.
Your CH will nearly triple in a year to 18 months. Then you will have to drain the entire pool and start over.

If you have a whole house water softener, I suggest you see if you can plumb your make up water to come from the softener.

Myself and some others use RV water softeners just for our pool so we do not have to drain every 18 months, give or take.

Thanks I will definitely not add any calcium but will check the source water for parameters.

Appreciate all the responses.

 

[flynwill]

I've been told by my Son who lives there that there are parts of Goodyear where the water is from a city-run reverse osmosis plant, so the CH in the supply water might indeed be quite low. I would recommend testing your fill water.

 

[TeamFreddy]

Following up with Source Water Details Below:

Source Water
PH 8.0
TA 180
CH 140

Todays Pool #s
FC 4..4
CC 0
PH 7.4
TA 140
CH 140
CSI -0.43
CYA - 35 (Tested 4/2)

 

[ajw22]

Your CYA is 40. We round up. If the dot disappears between 40 and 30 we call it 40.

The scale is logarithmic and halfway between lines is not 5. You cannot eyeball values between lines.

 

[mknauss]

Looks like you get a mix of waters. But with a CH of 140, I would still be hesitant to add any calcium. Try to keep the pH in the upper end of the 7's.

If you are insistent in adding calcium, do not go above 250 ppm. Your CH will still rise by 200++ ppm over the next year.

 

[TeamFreddy]

Your CYA is 40. We round up. If the dot disappears between 40 and 30 we call it 40.

The scale is logarithmic and halfway between lines is not 5. You cannot eyeball values between lines.

Thanks I figured I needed to round up.. just wasn't sure how far up so I called it 35. Ill bump it to the next one up.

 

[TeamFreddy]

Looks like you get a mix of waters. But with a CH of 140, I would still be hesitant to add any calcium. Try to keep the pH in the upper end of the 7's.

If you are insistent in adding calcium, do not go above 250 ppm. Your CH will still rise by 200++ ppm over the next year.

Got it, I will hold off on adding calcium. Just to confirm when you say. keep PH in the higher 7's you mean target 7.6-7.8 right?

 

[mknauss]

Just to confirm when you say. keep PH in the higher 7's you mean target 7.6-7.8 right?

yes. If the pH goes to 8 or above, do not lower it below 7.6. This will keep the TA higher and thus your CSI less negative.

Continue to monitor CH monthly. It will rise as you use the tap water to make up for evaporation.

 

[mknauss]

I assume you will be using liquid chlorine to chlorinate. You cannot use pucks, they are very acidic (and skyrocket your CYA).