Yellow stains to black stains to yellow again!

[TOC]

Hi!
A few weeks ago, when I was in the pool, I noticed a few small yellow green areas. It was slippery under my foot so I got out because I assumed it was algae.

Brushed the bottom of the pool and walls. Tested the water using an HTH 6-way test kit.

Available chlorine & Br. ZERO
pH: 7.5
Total alkalinity: 110
Total hardiness: 190
I ran out of the agent to test the CYA so I don’t have those levels right now.

Super chlorinated with liquid bleach and vacuumed to waste the next day. The stains lessened but didn’t go away.

A few days later, there were linear spots of yellow/green/brownish fine particles on the bottom of the pool.
Vacuumed to waste and brushed the walls again.
pH: 7.8
Cl/Br: over 5ppm

Waited for the CL/Br to come back down to 3ppm
Added 64oz of Chlorox algicide/clarifier combo
Let pump run for 24 hours.

Linear spots now powdery white color & yellow stains were faint but there. Vacuumed to waste.
A few days later, the yellow stains were turning black.

So I shocked the pool again with HTH granular shock, ran the pump for 12 hours and shocked again 72 hours later. The black stains completely went away.
The next day, the yellow stains were back and brighter. They do NOT come off when brushed.
Available chlorine & Br. >5ppm
pH: 7.8
Total alkalinity: 130
Total hardiness: 100

 

[PoolStored]

Welcome to TFP!!!

The first thing you need is a proper test kit. Here are the recommended kits. Link-->Test Kits Compared

Add 3ppm of liquid chlorine per day until the kit arrives. Nothing else.
When the kit arrives, follow the SLAM process to clear the pool. Link-->SLAM Process

AFTER you have completed the SLAM process, then use the stain guide on the stains. Don't try to address stains before the SLAM process.

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

 

[TOC]

Welcome to TFP!!!

The first thing you need is a proper test kit. Here are the recommended kits. Link-->Test Kits Compared

Add 3ppm of liquid chlorine per day until the kit arrives. Nothing else.
When the kit arrives, follow the SLAM process to clear the pool. Link-->SLAM Process

AFTER you have completed the SLAM process, then use the stain guide on the stains. Don't try to address stains before the SLAM process.

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

Thank you!! Going to liquid chlorine now. I was using it, but the local stores ran out!

 

[TOC]

I am back with an update. I completed a SLAM and all the yellow stains went away. Due to budget, I wasn’t able to purchase one of the testing kits you recommended.

Since there aren’t anymore stains that I can see, appears wouldn’t be able to now follow the Stain Guide.

 

[JamesW]

It might be something under the liner bleeding through.

Stains Behind Liner
Some stains are actually behind the liner, in between the wall or floor and the liner. They start as a bacterial colony, or can be algae or mineral crystals. If they are dark enough and large enough, they may show through the somewhat opaque pool liner and appear as a stain. Short of pulling up the liner and treating the floor, and foaming the walls, what can you do when the stain is behind or underneath the liner?

https://intheswim.com/blog/stains-and-discoloration-in-a-vinyl-liner-pool.html#:~:text=Stains%20Behind%20Liner,be%20algae%20or%20mineral%20crystals.

What causes staining or discoloration of the vinyl below the water line? | McEwen Industries

While all stains are either mineral or organic, the most common cause of staining and discoloration of your liner below the water line is secretions by micro-organisms. As these micro-organisms feed, they secrete dyes, which can be one of many colors that stain the vinyl. Although these stains...

mcewenindustries.com

What are the black stains on the floor of my liner and how do I get rid of them? | McEwen Industries

If you have black or grey cloud-like stains on the floor of your in-ground vinyl liner, they are most likely caused by bacteria that is living in the ground under your pool. Bacteria sometimes show up years after a pool has been installed. We think the bacteria can be washed into your pool area by

mcewenindustries.com

 

[TOC]

It might be something under the liner bleeding through.

Stains Behind Liner
Some stains are actually behind the liner, in between the wall or floor and the liner. They start as a bacterial colony, or can be algae or mineral crystals. If they are dark enough and large enough, they may show through the somewhat opaque pool liner and appear as a stain. Short of pulling up the liner and treating the floor, and foaming the walls, what can you do when the stain is behind or underneath the liner?

https://intheswim.com/blog/stains-and-discoloration-in-a-vinyl-liner-pool.html#:~:text=Stains%20Behind%20Liner,be%20algae%20or%20mineral%20crystals.

What causes staining or discoloration of the vinyl below the water line? | McEwen Industries

While all stains are either mineral or organic, the most common cause of staining and discoloration of your liner below the water line is secretions by micro-organisms. As these micro-organisms feed, they secrete dyes, which can be one of many colors that stain the vinyl. Although these stains...

mcewenindustries.com

What are the black stains on the floor of my liner and how do I get rid of them? | McEwen Industries

If you have black or grey cloud-like stains on the floor of your in-ground vinyl liner, they are most likely caused by bacteria that is living in the ground under your pool. Bacteria sometimes show up years after a pool has been installed. We think the bacteria can be washed into your pool area by

mcewenindustries.com

Hi!

Thank you for the input. It does in fact appear to be something bleeding through the liner. I believe it must be bacteria because it definitely goes away with the SLAM process but comes right back once the chlorine levels drop.

From all the research I’ve done, this does not seem to be treatable, and the liner might even be damaged at this point. I’m not 100% sure though. My guess is if it’s appearing through the liner, it must also be getting through the liner…???

It appears I need to drain the pool and move it, but there’s such varying opinion on how to best treat the ground below and what to put down to prevent it from happening again.

 

[JamesW]

My guess is if it’s appearing through the liner, it must also be getting through the liner…???

It can permeate the liner.

It appears I need to drain the pool and move it, but there’s such varying opinion on how to best treat the ground below and what to put down to prevent it from happening again.

In some cases, you can treat it with bleach or a chemical to kill the bacteria.

In some cases, you need to remove the bad spots and redo the floor.

 

[TOC]

I think if it is seeping thru the liner, I need to move the pool and treat the floor because chlorine only keeps it at bay for a few days to a week before it’s back.

And if it permeates the liner, does that mean I should replace the liner? Again, I’ve read such varying opinions.

 

[JamesW]

I need to move the pool and treat the floor

Is it an above ground pool?

And if it permeates the liner, does that mean I should replace the liner?

Most likely, the liner will need to be replaced.

How old is the liner?