Mottled Plaster??

[Flatlander]

The plaster is getting a mottled tan/brown look. It's been getting worse the last 6 months.
Today's water numbers are below. Pool store checked for metals-none. At 2 years old, I still have to add 1-2 cups MA daily or pH goes to 8.2+. Water-clear & 83deg.
Any ideas what to do??? Thanks, Mark

FC 4
PH 7.8
CH 450
TA 100
CYA 40 (low, SWG 55% at 8hrs/day)
Salt 3500

 

[YippeeSkippy]

Get yourself some Vitamin c tablets and stuff them in a thin sock and hold it against a stained area. Does it remove the stain? If so its metals.

In another stained spot- hold a chlorine puck against the area and see if after a few minutes if that doesn't lift it? If so its organic.

You can often buy individual pucks at Lowes or the pool store. Vitamin C from drug store.

 

[Flatlander]

Wow!! Thanks Skippy!!
Vitamin C sock took care of a stain in about 60 seconds.
What now? I hope there is a better way to fix other than me going all over the pool with the sock!!

Thanks again.

 

[YippeeSkippy]

Time to read --> Pool School - Metals in the Water and Metal Stains

 

[Flatlander]

Perfect!! Thank you, Sir

 

[YippeeSkippy]

Perfect!! Thank you, Sir

Ma'am actually Skippy is my other half :batman:

Do you have any idea how you got metals in the water? Have you used copper containing algaecide? Do you fill from a well??

 

[Flatlander]

Oops!!
Lol, I knew when I posted, that would be the case!!
Have a good weekend.

 

[Flatlander]

And I have no idea how the metals got there!! No to both of your questions. Could it have been at startup? Is a sequestering agent usual? I know my PB did not use any. I think my plaster needs a startup acid wash too. It was done but has never looked right. In 90% of the pool the blue is hidden.

 

[zea3]

Some algaecides have copper in them. Another way to end up with copper in the water is a degraded copper heat exchanger (from the pool heater) or degraded copper piping.

 

[Flatlander]

I think my problems are Iron stains, as they can be removed w Vitamin C.
And no blondes have turned green haired.

 

[zea3]

Sorry, don't know why I was thinking copper. I've answered a few copper questions today! Do you have well water or old iron pipes? Those are the most common ways iron enters the pool. Fertilizers containing iron can also cause problems if they get blown into the pool.

 

[Flatlander]

No well water or old pipes.
I have never seen any fertilizer streaks.
Is there any relationship w the pool "eating" muriatic acid after 2 years?
Leaching of iron from Okla red rock or rebar not encased someplace?
Those are far fetched I know!!

 

[Flatlander]

Moderator might want to move to Chemistry 201??

Ascorbic Acid treatment started:
6-23-16 FC1.5 PH7.5 Add 8c MA,16oz KemTech Algaecide
6-24-16 FC 0 PH7.2 Add 1lbs AA at a time, 3 lbs total to rid stain, 32oz Magic's Purple Stuff
6-25-16 FC 0 PH7.2 turn on SWG 10%, increase FC slowly
6-26-16 FC 0 PH7.2 SWG increase to 20%
6-27-16 FC 0 PH7.6 SWG increase to 30%, add 10c bleach
6-28-16 FC 0 PH7.6 SWG increase to 40%, add 10c bleach
6-29-16 FC 0 PH7.8
0645 add 5c bleach, 1.5c MA
0745 FC 0 add 5c bleach
0845 FC .5 add 5c bleach
0945 FC 1 add 5c bleach
1045 FC 1 add 5c bleach
1145 FC .5 add 5c bleach (sun is out caused drop??)

CYA I am sure is low but I am waiting to get to FC 3 before adjusting.

Any suggestions?? I want to dump 1-3 gallons of bleach in at one time but the TFP instructions stated to raise slowly. This is getting painful tho!!!
Thanks for any advice!!!