Feeling helpless with plaster stain

[stevegoods]

Hi All,

First, I'd just like to thank the members of TFP for being so incredibly helpful. After buying a home with a pool 4 years ago, this website/forum has saved me and helped me manage my pool. There was a point where I felt like a total expert. But then... I developed this staining in the deep end of my pool. I have attached a picture and I will outline where I am in the process. At this point I don't know what next to do and I am hoping someone might offer some guidance.

After reading about stains and what might cause them (bio vs. metal), my first approach was to drop a puck on it. Initially this was not generating any positive results. One thing I hadn't thought about was whether or not there was any danger to the plaster by leaving a puck on for too long. If you look in this picture, you will see clearly where I had laid pucks, but what I don't know is if this shows me that this is biological staining or if by leaving the puck in for too long I have actually damaged the plaster, essentially burning through the stain and the plaster itself. These puck marks have been there for some time now. What confuses me is if it was biological, why would it not go away after a full season in adequate levels of FC? That's what leads me to believe I may have done damage to the plaster.

For fear of it being metal, I added CuLator PowerPaks to help remove metal from the water. Also, on my top step there was some staining happening. I used a vitamin C tablet and it did help. It was then that I assumed the deep end was suffering from metal staining. Two days ago, I introduced ProTeam Metal Magic to the pool and as of today it's not doing anything. So here I am, confused on what I should do next.

If anyone has some ideas or guidance, I would be appreciative.

Steve

 

[ajw22]

The puck marks are there because it looks like it cleared the stain. I don't understand why you would expect the puck marks to go away.

The chlorine in the pucks does not damage plaster. There is also acid in trichlor and the acid sitting on the plaster may have etched the acid a bit. That is cosmetic damage, not structural damage to your plaster.

Normal FC levels in your pool, especially with CYA, are adequate to kill algae but are not strong enough to get rid of stains. You need to run higher levels of FC for a long period of time to bleach out organic stains.

Stains in Your Pool

The stained pool is beyond embarrassing. Our in-depth Guide to remove stains in your pool will help you to remove the stains and prevent them in the future.

www.troublefreepool.com

Says... To remove organic stains raise the FC up between 60% and 100% of shock level for your CYA, Chlorine / CYA Chart, and brush often, daily if you can.

Did you do that?

 

[stevegoods]

Hi,

It wasn't that I expected the puck marks to go away. I had the pucks on there for days and it wasn't doing anything. I think I had left them on for about a week or so. Even then when I removed them the spots were not like what you see in the picture. It faded a bit more over time. It was then, given how long this took, that it was more about perhaps burning through the plaster than simply killing what would be algae. Hope that makes sense.

But based on your feedback, sounds like I need to go with an elevated FC and scrubbing process and see how that gets on. I have not done that yet and will try it. Thanks.

 

[ajw22]

Hi,

It wasn't that I expected the puck marks to go away. I had the pucks on there for days and it wasn't doing anything. I think I had left them on for about a week or so. Even then when I removed them the spots were not like what you see in the picture. It faded a bit more over time. It was then, given how long this took, that it was more about perhaps burning through the plaster than simply killing what would be algae. Hope that makes sense.

That behavior of the stain describes organic stuff. May be some algae.

You need to brush algae or let the chlorine sit on it to breakdown the biofilm that protects it. Once you broke most of it down with the puck then the normal chlorine level in your pool was able to fade it some more.

Does your pool pass the Perform the Overnight FC Loss Test (OCLT) - Trouble Free Pool ?