Can't figure out stain

[Dr.Ron]

It looks almost like there is sand in the pool. THe sad part is last season we drained the pool and had the pool acid & power washed. Refilled (well water) and got chemistry good except battled high PH all season for the first time. Salt cell pool also. Opened this year and found the staining...but it's NOT in the deep end. Only on the bench seat, sun deck and the shallow end. Water test said calcium hardness is 200, iron 0.1, copper is 0.1 too. Need help!

 

[duraleigh]

You can't brush the stain off, right?

Do you have your own good test kit?

 

[Dr.Ron]

Does not brush off. I do have a test kit. I had the water tested at Leslie's. They said calcium hardness, iron and copper were all good.

 

[Dr.Ron]

Looks like sand is in the pool, but it's nothing loose.

 

[Texas Splash]

I do have a test kit.

Which test kit do you have? Please post a full set of results. For the staining specifically, you can try:
- Rubbing with a chlorine tab (organic/algae)
- Rubbing with a Vitamin C tablet (iron)
- Rubbing with dry acid in a thin sock (copper).

It looks more like calcium staining, perhaps with some organic material embedded, but some valid water test results might help confirm.

 

[Dr.Ron]

It's a basic test kit. I don't know the name..I've tried the chlorine tab and vitamin c tab tricks. They didn't touch it. Haven't tried acid in a sock yet.

 

[Dr.Ron]

 

[Dr.Ron]

That is the 2nd water test. I can't imaging that phosphate # is right. Last Friday it was 400.

 

[Texas Splash]

I'll preface this by saying that we place very little value or reliability on pool store testing. You may already know that. Having said that, the free chlorine level appears to be extremely low. Take a look at our FC/CYA Levels. Find your current CYA and the recommended FC range. Phosphates have very little to do with TFP pool care. As long as there is no algae, phosphates are irrelevant. Remember that TFP and pool store testing are not compatible - two different worlds of water management. A proper test kit really needs to be your next move if you can swing it. Makes a HUGE difference.

 

[Dr.Ron]

Ok. But the stains?
I had a pool co. Out and they said the water is now balanced. I had added conditioner.

 

[Texas Splash]

Whenever someone other than the pool owner says the water is balanced, I get nervous. I look to see if they used a TF-100 or Taylor K-2006C kit. Then I look at those results. But since you said you tried the Vitamin C and chlorine tab test, it's starting to look more like calcium scale.

 

[Dr.Ron]

Any recommendations?

 

[Texas Splash]

Any recommendations?

You might try an acid wash. This article outlines some thoughts.

Calcium Scaling

Calcium scale on your pool is something we all want to avoid. With some elbow grease and a pumice stone for pools we can help you remove this eyesore.

www.troublefreepool.com

 

[Dr.Ron]

We did that last year.
The stain has lightened slightly but is still present solidly.
I tried Jack's stain identifier but surprisingly it did not Id the stain!

 

[Dr.Ron]

No one else?
I started with a pool company for weekly maintenance. The water is perfectly balanced. The think it is a metal stain.

 

[Pool_Medic]

Have you dropped a bunch of chewable vitamin c tabs in one stained area? Sure looks like metal staining to my eye.

 

[Dr.Ron]

Have you dropped a bunch of chewable vitamin c tabs in one stained area? Sure looks like metal staining to my eye.

Yes. It didn't appear to do anything...but I will try again

 

[Poolbreh]

It looks organic to me. You said the water was perfectly balanced, but still haven’t shown us reliable test results.

 

[Dr.Ron]

Have you dropped a bunch of chewable vitamin c tabs in one stained area? Sure looks like metal staining to my eye.

So this morning I put some vitamin C tabs into a sock and smashed them up some. I added a rock and put it on a small stained area and when I went back tonight to look the stain was gone!

So what can I do to get rid of the rest of it now??

 

[Pool_Medic]

Lower Ph and chlorine, do an AA treatment, then resume proper chlorine levels according to your cya level.