Large gray spot in mini pebble

[MattNpool30]

Hi, I'm getting a new construction pool completed and I notice a large gray spot in the deep end on the new mini pebble. I 1st notice it the following day after my pool was topped off. My concern is can it be removed without draining the pool? It is about a 20k gallon pool with NPT stonescape tropics blue mini pebble. Pool was acid wash before it was filled.
Another thing, the pb wanted to know if I had pics of the gray spot when the water was being filled. The star up crew showed up a day and a half later and didn't leave the filter pump running. Also no instructions for brushing or maintenance.

 

[AQUA~HOLICS]

Have you tried to brush the stain? Trying to remove the stain with the water still in the pool should be your first attempt, if you don’t get the results you want then removing the water and power washing the area to see if it helps in removing the spot., if that has no effect then a light chemical wash, it appears that possibly the stain came from something that exited the main drains while the pumps were off and was able to sit on the plaster for hours.

 

[MSchutzer]

That looks like an area where water would sit in the deepest part of the pool.
After they did the acid wash did rinse the surface well and use a submersible pump to remove all the remains of the acidic water from the pool?
I wonder if some of the acidic wash solution sat in a pool in the deep end for an extended period of time. I’m don’t know why that would change the color unless excessive plaster was taken off?
It sure looks like something pooled there causing the plaster discoloring.

 

[MattNpool30]

Have you tried to brush the stain? Trying to remove the stain with the water still in the pool should be your first attempt, if you don’t get the results you want then removing the water and power washing the area to see if it helps in removing the spot., if that has no effect then a light chemical wash, it appears that possibly the stain came from something that exited the main drains while the pumps were off and was able to sit on the plaster for hours.

My pb isn't Johnny on the spot with this situation and also my pool pump is off and the pool values were left closed. I'm wondering if the plaster is compromised and the pb is backing off the job? They have most of my money for the pool. It helps if the pb response to my calls.

 

[MattNpool30]

That looks like an area where water would sit in the deepest part of the pool.
After they did the acid wash did rinse the surface well and use a submersible pump to remove all the remains of the acidic water from the pool?
I wonder if some of the acidic wash solution sat in a pool in the deep end for an extended period of time. I’m don’t know why that would change the color unless excessive plaster was taken off?
It sure looks like something pooled there causing the plaster discoloring.

Their was a sump pump placed in the deep end of the pool during the acid wash and rinse. I'm not sure how well he rinsed the deep end. Their is a possibility of some type of water coming out of the 2 suction lines. Maybe the acid liquid got trapped in the lines then seep out during the pool fill?

 

[ajw22]

I'm wondering if the plaster is compromised and the pb is backing off the job?

The plaster is not "compromised".

The grey area is cosmetic.

How deep is that area? If you can reach the floor then try sanding the area with 80/100 grit wet/dry sandpaper and it will expose new plaster with the color.

The pool builder may offer to give the pool and acid wash. You really don;t want to do that as it will etch and roughen the plaster.

@onBalance

 

[onBalance]

Inasmuch as this is a brand new pool, do not attempt to remove that discoloration yourself as it might void the warranty. It is up to the PB to resolve. However, they should get your permission before doing anything that might be detrimental to the plaster finish such as an acid wash.

 

[MattNpool30]

The plaster is not "compromised".

The grey area is cosmetic.

How deep is that area? If you can reach the floor then try sanding the area with 80/100 grit wet/dry sandpaper and it will expose new plaster with the color.

The pool builder may offer to give the pool and acid wash. You really don;t want to do that as it will etch and roughen the plaster.

@onBalance

The deep end is about 6 1/2 feet give or take. I hoping the pb acts in good faith and would take care if it, but this pb is a tightwad, and I had to fight him on a few things already.