Take a piece of 2" PVC pipe and put one end down into the pool and then pour muratic acid in the other end. After about 20 seconds you will see the acid coming out the other end. If the stain comes off then is was calcium or alkalinity that stained the pool. If it does not come off then it could be internal. They may have used a mixing drum that they did not clean out properly from a gray plaster. That will leave more like small streaks than anything and does not get worse. It shows up right away and then stays that way.

My money would be on calcium. That is what the staining looks like.

What is your calcium reading out of the tap? Was a sample of the tap water taken before they added chemicals to the pool? What was the start up procedure like? It normally takes 7 to 10 days of constant monitoring and chemical adjusting.

Some parts of Southern California especially Orange County the water really varies. It can be high in calcium.

White plaster has white cement, white sand and white marble aggregate in it. Unless the drum is contaminated I would bet on an external source for the stains.

wendypool,
Pools94 has it about right. I would suggest one thing before you replaster. Lower the ph to about 2 and let the pool set for 4-5 days. Sometimes this can scour the surface and create an even color. I have also used a sump pump to recirculate the water while lowering the ph. It's a pretty common practice. Good luck.

wendypool,
Most tap water can be adjusted in the pool after filling. Some tap water is very low in Calcium. This can be adjusted while the pool is filling by adding Calcium. Low Calcium water filling the pool can draw calcium out of the plaster.
Calcium is the usual accelerant for plaster contractors. This combination of low calcium fill water and 2% calcium accelerant could be a contributing factor to the look of the plaster. Area drought causing falling water tables can affect water quality. I've seen changes in calcium levels in fill water drop by as much as 100ppm which does affect the pool start-up process.
Over trowling and hydration issues are mostly seen in the bowl of the pool where water sits before plaster and where laborers are pushing plaster up the wall more aggressively. Check cracks are common in hot weather on steps and benches because they are covered with water last as the pool fills. These will look like egg shell crazing.
Pebble finishes have stone held by plaster (mortar) and have a harder finish because stone is harder than plaster. These products look great and have less moudling because of the stone finish and the acid wash they receive. Poor application is the downside and occasionally result in loose stones being common.
Still think that your problem can be solved by lowering the ph for a period of time to resolve the surface color issues.
Good luck.

You do have a hydration issue. Golfgeek is correct regarding what is commonly called a low alk treatment. You have mosture trapped behind the plaster causing your discolouration. What you will see is when you drop the ph to around two and your alk in the 20-30 range is over the next 48 hours their will be a chemical burst from the wall reliesing the "scale" from the wall allowing for proper hydration of the plaster. Most of the "stains" will dissapear and you then will be able to re-balance your pool. Make sure you bring the alkalinity up slowly over several days. It will also be advisable to add a quart of metal out per 10k gallons during this process. Calcium is a metal and this product will help your filter to collect it. Make sure after your pool is ballanced you clean your filters as they will have scale trapped in them.

best of luck

Thank you for your response Lonewolf126.

My plaster is now a year old. Is this process still an option?

So, you are saying that this process will actually soften the hardened surface to let the trapped water out? Have you done this successfully before on plaster that is a year old? And, are you saying that the stains will be completely removed and I will be back to white plaster?

Can or is it possible that this process may harm or damage any plumbing or other pool components?

What about the tile?

How will this process affect the Integrity and overall life of the plaster? Compared to just doing new plaster.

My pool was completely re-plumbed, all equipment is new, including tile work, coping and deck. Is this process you're suggesting a foolproof method for returning the plaster to white without affecting it's integrity or life expectancy or harming or aging any of my new work?

Would you recommend this over new plaster?

If I do new plaster, do you have any suggestions on how to prevent this problem from happening again?

Thank you.

Thank you for your response Lonewolf126.

My plaster is now a year old. Is this process still an option?

So, you are saying that this process will actually soften the hardened surface to let the trapped water out? Have you done this successfully before on plaster that is a year old? And, are you saying that the stains will be completely removed and I will be back to white plaster?

Can or is it possible that this process may harm or damage any plumbing or other pool components?

What about the tile?

How will this process affect the Integrity and overall life of the plaster? Compared to just doing new plaster.

My pool was completely re-plumbed, all equipment is new, including tile work, coping and deck. Is this process you're suggesting a foolproof method for returning the plaster to white without affecting it's integrity or life expectancy or harming or aging any of my new work?

Would you recommend this over new plaster?

If I do new plaster, do you have any suggestions on how to prevent this problem from happening again?

Thank you.

wendypool,
I would suggest that the contractor make all efforts to avoid another replaster. Generally speaking, I would not perform a second replaster without chipping out all of the existing plaster. A third coat of plaster is asking for problems in the future because the bond coat under both previous finishes has to hold up for a long time. I personally don't have that much confidence that it will.
Most good plastering contractors are well versed regarding the startup techniques for various types of plaster.
I'm assuming that your remodel included a bond coat replaster and not a full chip out. If they used a bond coat, do you know if it had ever been replastered before?
Lowering the ph is done with the equipment off. Low ph can affect copper fittings and it is possible that you may see etching on the tile if you have used stone tile. Grout may also be etched slightly. Your PB are plaster contractor should be able to explain what is commonly referred to as an "acid start-up". If the problem is topical as we think, then yes it should be effective.

quote" Can or is it possible that this process may harm or damage any plumbing or other pool components? quote

The only way you wlii damage your plasters finish is if you used too much acid directly applied to dry plaster. When it's mixed in with all the water it just crashes the PH and ALK.
Now, if you don't raise your levels back up to acceptable levels afterwords it will eat up the inside of your pool heaterr' heat exchanger and make your plaster rough..

We've encountered your situation several times after a new startup.
I've always drained the pool asap then gone around the pool finish with a broad flamed torch several times daily for a few days, refilled, and used a hot start aka "acid start-up".
Yours looks way worse than anything we've seen. You may have to go through the process decribed and then after releasing the stain, drain and torch.

See ya,
Kelly

My plaster was done with a complete chip out.

It sounds like any option other than a complete chip out and replaster is a dice roll with potential side effects and not the "new white plaster job" I paid for.

Thank you gentlemen. Based on the comments, it definitely seems like my best option is to chip out and replaster. This time, making sure they test the water prior to the fill and watch the amount of accelerant that is added to the plaster.