Calcium/Scale?

[Steenbot]

30k gallon salt water pool, new vinyl liner installed 1 month ago.
FC 4.5
CC 0
PH 7.6
TA 200
CH 325
CYA 35
Running my SWG at 50%, backwashed last night, Pool heater at 80 degrees.

I’m having trouble with scale or calcium or maybe that’s the same thing, it is white, fine, gritty and cloudy when brushed, my dolphin picks it up. There is a lot of it gathering on my steps and in the corners of the pool.

I “think” it is from high PH 8.0-7.8-7.6 tested just tonight and TA hovering at 225-200 tested just tonight. I’ve been adding 1/2 gal of muratic acid daily about every other day. Does this sound like the correct plan of action? I’m trying to get my PH down to low 7 and in the process bring down my TA then bring the PH back up with aeration without raising my TA again as per TFP.

Do I need to be more patient with the numbers? This scale, Calcium bothers me, I don’t want to mess up the pool!

Really appreciate your kind thoughts and advice!

 

[proavia]

Welcome to TFP!

If your CYA test is over 30 and less than 40, round up to 40. The test tube scale is logarithmic, not linear.

Find the target range for your CYA - FC/CYA Levels
Dose chlorine (adjust SWG or add liquid chlorine) for the top end of the target range.

Can you gather some of the stuff up?
If so, place it on the ground or rocks and put a few drops of muriatic acid on it. If it fizzles, it's calcium.

As for lowering the TA - it can take a while. Pool Owner Patience - POP - is required.

 

[PoolStored]

I’m having trouble with scale or calcium or maybe that’s the same thing, it is white, fine, gritty and cloudy when brushed, my dolphin picks it up. There is a lot of it gathering on my steps and in the corners of the pool.

I “think” it is from high PH 8.0-7.8-7.6 tested just tonight and TA hovering at 225-200 tested just tonight. I’ve been adding 1/2 gal of muratic acid daily about every other day. Does this sound like the correct plan of action? I’m trying to get my PH down to low 7 and in the process bring down my TA then bring the PH back up with aeration without raising my TA again as per TFP.

Do I need to be more patient with the numbers? This scale, Calcium bothers me, I don’t want to mess up the pool!

Really appreciate your kind thoughts and advice!

Yes, it is possibly scale, even in a vinyl pool. Assuming your water temp is 80, your CSI is .52...which is likely scaling territory.

@proavia is on the right track. See if acid fizzles and reduce TA. You can put it in some tin foil and add the acid to test for fizzle.

The trick to lowering TA is LOTS of VERY TINY bubbles. I built this rig on a sump pump and I can reduce TA in a 30K gallon pool by 10ppm in 12 hours. Reduce pH to 7.0, aerate to 7.2 or 7.4, rinse repeat. Works because CO2 outgases at the highest rate between 7.0 and 7.4.

Aerator.jpg

• PoolStored
• Jul 5, 2022

 

[Steenbot]

Welcome to TFP!

If your CYA test is over 30 and less than 40, round up to 40. The test tube scale is logarithmic, not linear.

Find the target range for your CYA - FC/CYA Levels
Dose chlorine (adjust SWG or add liquid chlorine) for the top end of the target range.

Can you gather some of the stuff up?
If so, place it on the ground or rocks and put a few drops of muriatic acid on it. If it fizzles, it's calcium.

As for lowering the TA - it can take a while. Pool Owner Patience - POP - is required.

Thank you so much for responding and the tip about reading CYA! The material fizzes with the addition of Muratic acid so def calcium. I used the link for the FC/CYA target range using a SWG it says my CYA should be around 60. Wow! I read horror stories about too much CYA so I’m hesitant to add. Testing today gives me FC 5 PH 7.6 TA 200-225 CYA 30 so my numbers are coming down but I’m still getting copious amounts of calcium in the pool.

 

[proavia]

I see you have shared your PoolMath log here.
Continue entering and saving your test results to PoolMath each time you test (even if not doing all the tests).

A CYA of 70 is fine with a SWG. It will help the chlorine to burn off slower. You aren't using 3" tabs or granular chlorine, so aren't adding any CYA. As long as you keep FC in or slightly above the target range for your CYA level, you are good.

With your high TA, work on bringing TA down to around 70. Once TA stabilizes around 60-70, your pH rise will slow.
See what @PoolStored suggested above.

In PoolMath, be sure to track CSI, Salt, Combined Chlorine and Water Temperature.
To help prevent scaling in your SWG (and reduce or possibly eliminate the calcium buildup you're seeing), keep the CSI in the 0.00 to -0.30 (negative 0.30) range.

Add manufacturers and model numbers for your equipment to your signature.

What is the pH, TA and CH of your fill water?

 

[Steenbot]

I see you have shared your PoolMath log here.
Continue entering and saving your test results to PoolMath each time you test (even if not doing all the tests).

A CYA of 70 is fine with a SWG. It will help the chlorine to burn off slower. You aren't using 3" tabs or granular chlorine, so aren't adding any CYA. As long as you keep FC in or slightly above the target range for your CYA level, you are good.

With your high TA, work on bringing TA down to around 70. Once TA stabilizes around 60-70, your pH rise will slow.
See what @PoolStored suggested above.

In PoolMath, be sure to track CSI, Salt, Combined Chlorine and Water Temperature.
To help prevent scaling in your SWG (and reduce or possibly eliminate the calcium buildup you're seeing), keep the CSI in the 0.00 to -0.30 (negative 0.30) range.

Add manufacturers and model numbers for your equipment to your signature.

What is the pH, TA and CH of your fill water?

Ok so I need to add conditioner to get my CYA up, I can do that. Looks like I need to get more acid to keep dropping the PH to 7.0 and then aerate.
I will update my signature with info requested.
Fill water is from a well
PH 7.0
TA 350-375
CH 25
Thank you again, really appreciate you!

 

[proavia]

The good news is your fill water CH is low.
The not so good news is your fill water TA is quite high.
Based on your evaporation rate, you will need to work on lowering TA regularly. Having a way to aerate (based on fill water pH of 7.0 and TA 350-375) will be important.

No need to adjust CH upwards with a vinyl liner. If you had a heater, its manual would probably state a minimum CH range.

 

[Steenbot]

Yes, it is possibly scale, even in a vinyl pool. Assuming your water temp is 80, your CSI is .52...which is likely scaling territory.

@proavia is on the right track. See if acid fizzles and reduce TA. You can put it in some tin foil and add the acid to test for fizzle.

The trick to lowering TA is LOTS of VERY TINY bubbles. I built this rig on a sump pump and I can reduce TA in a 30K gallon pool by 10ppm in 12 hours. Reduce pH to 7.0, aerate to 7.2 or 7.4, rinse repeat. Works because CO2 outgases at the highest rate between 7.0 and 7.4.

Aerator.jpg

• PoolStored
• Jul 5, 2022

This is fantastic! Thank you for your kind helpful reply!

 

[Mattikuss]

Yes, it is possibly scale, even in a vinyl pool. Assuming your water temp is 80, your CSI is .52...which is likely scaling territory.

@proavia is on the right track. See if acid fizzles and reduce TA. You can put it in some tin foil and add the acid to test for fizzle.

The trick to lowering TA is LOTS of VERY TINY bubbles. I built this rig on a sump pump and I can reduce TA in a 30K gallon pool by 10ppm in 12 hours. Reduce pH to 7.0, aerate to 7.2 or 7.4, rinse repeat. Works because CO2 outgases at the highest rate between 7.0 and 7.4.

Aerator.jpg

• PoolStored
• Jul 5, 2022

This rig is fantastic. I just noticed scale floating around my pool and I’m trying to figure out the science behind how alkalinity is related to calcium hardness. I have a vinyl pool and never checked CH because I didn’t think it applied to me.