IG plaster - staining

[neen01]

Our pool is 12 years old. There is a bit of staining around the infloor drains that just looks like dirt. These are the darkest stains.
The sides of the pool have some light yellowish streaks - wide, solid and all the way down as if someone painted on it - not like algae
Other parts have darker lines like white dishes get when scratched.

Is it normal for the plaster to get imperfect/dirty over time?
I remember reading about pumis and vitamin c for certain stains so will try that too. It will be hard to do on the drains as the pool is 9 ft
It doesn't come off with brushing (even a metal brush) so I didn't think it was a kind of algea - also the pool passes the overnight test after slamming it so that means it isn't algea right?
We only opened it a week ago and in the past it has looked not as bad as the season goes on but seems to be trending worse each year we open it.
I tried to take pictures but it looks fine in the pictures besides the ones around the drains. I am not sure if my phone isn't good enough or the stains are that light

 

[ajw22]

It looks like 12 year old plaster to me. You can try various stain treatments but I don’t think you will make much improvement. Lots could have happened between the water and the plaster over 12 years.

How does your water chemistry look?

 

[neen01]

It looks like 12 year old plaster to me. You can try various stain treatments but I don’t think you will make much improvement. Lots could have happened between the water and the plaster over 12 years.

How does your water chemistry look?

water chemistry is fine and was last year
i see in your signature that you replastered after 17 years - is that what the solution ultimately is? what is that process like? average cost?

 

[ajw22]

water chemistry is fine and was last year
i see in your signature that you replastered after 17 years - is that what the solution ultimately is? what is that process like? average cost?

My observation is plaster lasts 15-20 years in the Northeast. I have redone 2 pools in that range and have friends in the area with similar experience.

If it is the first layer of plaster and adhesion is not an issue then it is about a 5 day process to drain the pool, clean and prep the old surface, apply a bonding coat, lay new tile on steps, apply plaster, fill with water. Cost can be $10K-$15K depending on finish. There are just a few plaster crews in the area who all the pool companies subcontract to. This assumes you don’t need tile or coping repairs also.