Stains in SWG pool

[CathyS]

I have an SWG pool which has some stains that are possibly organic. I have been reading a lot of the information on the TFP site. Thank you for this site. It is very informative. I have increased the chlorine in my pool and purchased a stainless steel brush because some of the stains looked like they might be black algae. Some of the stains have disappeared and others have lightened. But I still have some stains that are not going away. I am wondering if I need to do a SLAM. I just got my Taylor K-2006 test kit today. My CYA is 80 and my FC is 7 ppm. Do I need to lower my CYA before I can do a SLAM?

 

[jeffchap]

Before you begin a SLAM, Perform the Overnight FC Loss Test (OCLT)

What does your CC measure?

Is the water clear?

 

[CathyS]

Before you begin a SLAM, Perform the Overnight FC Loss Test (OCLT)

What does your CC measure?

Is the water clear?

Before you begin a SLAM, Perform the Overnight FC Loss Test (OCLT)

What does your CC measure?

Is the water clear?

The CC is 1. And yes, the water is clear, although it wasn’t before I raised the chlorine level.

 

[CathyS]

So the Overnight FC Loss Test will tell me if I have Algae in the pool. If the stains are caused by metal or scale then I would not lose chlorine. Of course, there could be both at the same time I guess. Okay, thanks.

 

[Texas Splash]

Yes, continue with the Overnight Chlorine Loss Test first. Keep your FC in the 7-9 range today. Sounds like your water could use it anyways. Even if you have some metal issues, you need to address the algae first (if necessary). Tomorrow let us know how your OCLT goes. Also be sure to update your signature. See ours as examples. When you post your next results, please post everything as follows:

FC
CC
CYA
PH
TA
CH

We'll be watching.

 

[CathyS]

Thank you. Okay, I thought I did update my signature twice now. Perhaps I’m not doing something right?

 

[Texas Splash]

I thought I did update my signature twice now. Perhaps I’m not doing something right?

Hummm. If you post it here in the thread I'll copy & paste it for you.

 

[Rancho Cost-a-Lotta]

Try this link: https://www.troublefreepool.com/account/signature

You're probably filling out the "about me" section in your profile. The signature is different. Your's currently says "Minimom". If you're on a cell phone, signatures will only appear when you hold the phone sideways (landscape mode).

 

[CathyS]

Hummm. If you post it here in the thread I'll copy & paste it for you.

I’m assuming by signature, you mean, for example, yours is Texas Splash. If that’s the case, mine would be Mimimom.

 

[CathyS]

I’m assuming by signature, you mean, for example, yours is Texas Splash. If that’s the case, mine would be Mimimom.

Fat thumbs. Minimom

 

[CathyS]

Hummm. If you post it here in the thread I'll copy & paste it for you.

I just looked up how to create your signature. I already did that. There may have been a couple of things that I left out; is that the problem?

 

[Rancho Cost-a-Lotta]

The signature appears under each one of your posts. If you can't see it, turn your phone sideways. Yours says Minimom. Take a look at mine. We would like specific information regarding your pool in that signature block.

https://www.troublefreepool.com/account/signature

 

[Rancho Cost-a-Lotta]

I meant to post this link. Sorry.
Create Your Signature - Further Reading

 

[CathyS]

Yes, continue with the Overnight Chlorine Loss Test first. Keep your FC in the 7-9 range today. Sounds like your water could use it anyways. Even if you have some metal issues, you need to address the algae first (if necessary). Tomorrow let us know how your OCLT goes. Also be sure to update your signature. See ours as examples. When you post your next results, please post everything as follows:

FC
CC
CYA
PH
TA
CH

We'll be watching.

I did the OCLT last night. No chlorine loss. Here are my before and after results:
Before After
FC 7 FC 7
CC .6 CC .5
CYA 80 CYA 80
PH 7.8 PH 7.8
TA 120 TA 110
CH 280 CH 250

For the past week I had my SWG at 100 percent and I had also put in liquid chlorine. The FC was staying at 7. I'm guessing I need to lower my PH and TA. But you tell me. And at what point can I lower the SWG percentage? Also, something I have learned from Trouble Free Pools is that I'm not supposed to use dry acid to lower my PH because I have a SWG pool. I never knew that. That is what I have always used. So if I use Muriatic Acid, is there a special Pool Muriatic Acid that I should use? Thank you for your help with this.

 

[Bperry]

I did the OCLT last night. No chlorine loss. Here are my before and after results:
Before After
FC 7 FC 7
CC .6 CC .5
CYA 80 CYA 80
PH 7.8 PH 7.8
TA 120 TA 110
CH 280 CH 250

For the past week I had my SWG at 100 percent and I had also put in liquid chlorine. The FC was staying at 7. I'm guessing I need to lower my PH and TA. But you tell me. And at what point can I lower the SWG percentage? Also, something I have learned from Trouble Free Pools is that I'm not supposed to use dry acid to lower my PH because I have a SWG pool. I never knew that. That is what I have always used. So if I use Muriatic Acid, is there a special Pool Muriatic Acid that I should use? Thank you for your help with this.

Did you turn off the SWG before you started the OCLT? Just want to make sure, you wouldn’t be the first to forget that.

There’s no need to adjust the pH or the TA. As long as the pH starts with a “7”, it’s fine and the TA will slowly decrease over time as you manage the pH. There’s no special pool muriatic acid, you can get from Home Depot or the pool store depending on which is cheaper.

 

[Texas Splash]

So to confirm, the SWG was OFF last night during the OCLT correct?

 

[CathyS]

Did you turn off the SWG before you started the OCLT? Just want to make sure, you wouldn’t be the first to forget that.

There’s no need to adjust the pH or the TA. As long as the pH starts with a “7”, it’s fine and the TA will slowly decrease over time as you manage the pH. There’s no special pool muriatic acid, you can get from Home Depot or the pool store depending on which is cheaper.

Yes, I did turn off the SWG. What about my CH? Is that too high? According to the Taylor Water Balance calculator, my saturation index is too high. "Water may become cloudy or deposit scale." I am wondering if the stains that are still present in my pool on my steps are scale.

 

[CathyS]

So to confirm, the SWG was OFF last night during the OCLT correct?

Yes.

 

[Texas Splash]

You CH is fine. Higher water temps and the pH in the upper 7s is really why the CSI may appear to be slightly positive. Each time you lower the pH it lowers the CSI. Over time, as the TA slowly falls, it will also help. Nothing to be overly concerned about right now.

Your test results look good overall, and passing the OCLT is a great thing. If the stains are organic, it will just take time. You can add some additional liquid chlorine from time to time to increase the FC to about 10-12 and brush often which might help. If the stains only get worse or do not respond to chlorine, try rubbing with a Vitamin C tablet to see if it's iron. You're not on a well are you?

 

[CathyS]

I had to look up what CSI was. I thought that was a TV show! Now I understand. I am not on well water, and I have tried the Vitamin C tablet which did not work on these particular stains. They have gotten lighter after leaving a chlorine puck sit on them for a while and then brushing. But that does not affect all of them. If it's scale, how do I know that and how do I get rid of it? I will send a picture.