Pool Color Changed

by Linda

Last year I contacted you about our pool having a very green tint after it was acid washed by our pool maintenance guy. At this point it is still an aqua color with more green than blue in it, especially with direct sunlight. Originally. Having a white plaster with a medium gray marbled plaster color, the pool was a nice shade of medium blue. Since the acid wash the color has never returned to blue. All chemicals are good.

There are no algae, no excess metals. He also tried an acid "bath", I believe an acid wash after the pool was refilled. The consensus of several local pool builders and service people seems to be that somehow the gray part of the plaster took on a more green/gray color after the acid wash (the first one with pool drained). It is sparkling clean, but just a kind of weird color.

My question is: why would acid washing change the plaster color? Is there any way to restore it to blue without replastering? I have seen a product that gets "painted" on, a type of epoxy I believe. However, we don't want to create a new problem. Would appreciate your thoughts on this. I would also be able to do a phone consultation if you prefer.

Thanks for the follow up Linda

As the original post went, when an acid wash is done on a pool surface a layer of calcium carbonate will be stripped away. This allows the color that is underneath to show. What we're dealing with is a very thin layer of paint, perhaps a few millimeters in thickness. If the plaster is white or grey underneath then that color may start to show through as the blue is stripped away.

Concerning an "acid bath" after the pool was refilled, did the pool guy do an "acid start up"? This is a common method used to start a pool back up again after replastering. Many times pools with darker plaster will use a bicarbonate start up. This is a relatively new approach. I've only done acid start ups but I've heard some good things about this process. The bicarb doesn't seem to bleach like the acid would. I would start with the company/person who may have done the start up and ask what process was used.

As for getting the original vivid blue color back you would need to drain the pool and start over again. There's no product that I'm aware of that will bring color back to plaster.

Many epoxy paints require a 2 step process and they need to be mixed perfectly and the surface must be prepped or blistering/peeling can occur with a matter of a couple of weeks. What you don't want to do is simply paint over the already existing paint with another kind of paint. Many of these are not compatible and can cause issues down the road. The #1 reason for peeling/blistering paint is a poorly prepped surface.

It's obvious that you have consulted with several pool builders and techs (which is good) in your area and there seems to be a consensus. Being that they are there and possibly have a visual of the pool it would probably be best to take what they have already said. The only overriding factor is the acid wash did (and always will) strip a layer away causing a lighter layer to show through.

I'm never one to turn money down for a consult but I honestly can't think of anything different I would say on the phone that has not been covered in our emails. That being said, here's the link if you choose to do a personal consultation.

Pool Consultation

Hope this helps and have a great Summer.


Comments for Pool Color Changed

Average Rating starstarstarstarstar

Click here to add your own comments

Apr 20, 2015
Why Is Pool Changing Colors
by: Linda

Thank you for answering - and for your honesty! One thing I want to clarify is that the pool was never painted blue. It was a white plaster that was then painted with a medium gray in a "marbleized" effect to make the reflection of the sky appear a darker blue. What puzzles me is that the acid washing seemed to alter the gray color, giving it a yellow green effect which is changing the water color (at least we think that's what happened. No one has drained the pool again). I do believe the pool guy last year either did an acid start up or a later acid bath.

The product I saw online is a poly covering, no primers, claims to be used in water parks etc. I actually talked to the guy on the phone, older gentleman (maybe at least my age!) and he seemed pretty genuine. As you may see, I'm on a mission!

I understand now and I've seen those kinds of finishes. They're very attractive. I looked at the link and it's an epoxy paint which is one of the more difficult paints to work with for the reasons already stated. I've used it a few times and can't say I like to deal with it. At the Y I used rubber based paint which worked well for high traffic areas.

The link also says "High Performance Hybrid-Epoxy Coating". Hybrid seems to be the catch phrase now. I tried to get the MSDS online but can't find anything. The product might be from Rust-Oleum which is a good brand of paint. It did give a few bullet points of:

Covers in one coat!!!

• Easier Surface Preparation and Application.
• Requires no primers, top coats or sealers.
• Acid washing is not suggested or recommended.
• 15 year factory warranty.
• Use on concrete, gunite, aggregate or fiberglass.

If the chemicals are right what you're probably seeing is an optical illusion with the water. The water will take on the color of the finish due to the refraction and reflection of the light in the water, similar to when you put a stick in the water, it seems to bend. I had a pebble tec pool on my route that was almost black which caused the water to appear black, even at 1pm. It was difficult to tell whether the pool was dirty or not because the surface and water were so dark.

At any rate, hope this helps out and perhaps points you in the right direction. Good luck with your mission.


Click here to add your own comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Swimming Pool Paint.

Mobile & Desktop eBooks Are Perfect For Your Pool Start-Up!!

swimming pool care, basic pool care, above ground pool maintenance, inground, salt water

Click Here To Learn How This eBook Can Save You TONS Of Time & Money

Click Here To Learn The Best Way To Clear Up Your Pool 

Recent Articles

  1. Water Coming Out Of Backwash Hose & Meteor Sand Leaking

    I have a sand filter and water keeps coming out my backwash hose on every setting except recirculate. Water is still coming out the filter hose. The pool store can't figure it out.

    Read More

  2. Why Is There Sand At Bottom Of Pool

    How could I clean the sand out of the bottom of my above ground pool

    Read More

  3. Green Water with Copper | Pool Rx System

    THere is 0.32 ppm Cu(ii) in pool. Can this level of Cu(ii)turn water to grean?

    Read More