White or Light Blue Pool Stains

[jwm]

I purchased a new house with a pool during the winter, I opened the pool to find these white or light blue stains on the dark plaster surface.

I can't tell if the stains are white or light blue, they could be light blue because that is their natural color or because it is a white stain on top of a dark blue plaster surface.

The stains are very smooth to the touch (which might indicate they were deposited on the pool) and while they cover the entire pool, they are more "dense" in the spa.

Do I need to resurface the pool or are these stains that can be removed or sequestered / and then filtered out of the pool.

pH 7.2
FC 7.0
CC 10
TA 50
TH 100
CYA 80

These are the results from an aquacheck test strip. New "forum-approved" kit coming in the mail soon.

I previously owned a pool in a prior home.

Pool Size, 15,000 gallons (guess), IG, Plaster, DE Filter (trying cellulose media for the first time), Pool Installed 2004?, Spa, Polaris, Propane Heater

Pictures below:

 

[jblizzle]

Welcome to TFP!!!

So the light and dark areas have the same texture?

I think this looks like possible metal staining.

 

[duraleigh]

My initial reaction is it looks like a failing paint job.

 

[jblizzle]

I had that same thought based on the streaks, but thought that may show some type of pealing ...

 

[jwm]

This is a gunite pool with no paint. The stains are almost the same to the touch as the remainder of the pool surface. Let me know what you think.

 

[jblizzle]

Have you ever had the pool water tested for metal? Any reason to believe you have a lot of metal in the water? Use a lot of algaecide, or a mineral system?

 

[jwm]

No reason to believe I have alot of metal in the water. There is no mineral system, but again I inherited this pool for the first time this year. What would be the best way to go about testing the pool water for metals?

I tested with a TF-100

pH 7.5
FC 16
CC 0.5
TA 70
CH 170
CYA 90-100?

 

[jblizzle]

Have a pool store test for metals ... or try to put vitamin C on the surface and see if the color fades.

Hard to tell is the pool is supposed to be white or blue ...

 

[Richard320]

I see someone took a harsh wire brush to a painted surface.

What do you see?

:jocolor:

 

[jwm]

The pool is supposed to be the dark blue color. The light blue appears to be something deposited on the pool surface or a stain. The feel of the plaster surface is not consistent with someone taking a wire brush to it. That would be some heavy duty brushing, and I think it would be impossible not to leave some surface irregularities as evidence of any scrubbing that would of occurred.

What would cause light blue or white stains on a dark blue pool marcite surface?

 

[jblizzle]

Oh ... well in that case it is likely calcium scaling that is the white stuff. I thought that there was confusion what color the pool was actually supposed to be.

If you lower the water enough to expose some of the white stuff, trying putting a little muriatic acid on it and see if it bubbles up and removes some of the white.

 

[onBalance]

It may more likely be a dark blue plaster finish where the color pigment has simply "leached" out of the plaster surface, which exposes the original white cement color.
The lighter areas are probably more porous than the dark areas which are more dense and smooth.

If enough sanding is performed, it may eventually remove enough plaster to expose where the color pigment is still present, which would then look dark again.