Cannot control staining, please help (Pic included)

[tangouniform]

Backstory: I'm military and was deployed from Jan-May. During that time, we had a cover over the pool that loosened over time, allowing a lot of leaves, dirt, and other debris in the pool. When I got home, I removed the cover and saw all the debris on the bottom. I started the SLAM process at the same time I had the vacuum going to remove all the stuff off of the bottom (I think this may have been a mistake, probably should have vacuumed first). On day two of the SLAM, the water cleared up pretty well and I noticed stains on the bottom of the pool. No big deal I thought, there was still a lot of dirt on the bottom and I'm sure it'd clean up. After the SLAM was complete, the stains still remained. No type of brush, vacuum, or even pressure washer could remove them.

Fast forward 2 months now, and the stains still remain and have gotten worse throughout the entire pool. I decided to do another SLAM to see if perhaps there was some lingering algae that I never got rid of throughout the summer. The SLAM didn't help. Below are my pool stats. I know my CSI is extremely high right now, but I think that is due to the SLAM (specifically the pH). The zero CYA is killing my chlorine levels, but I have some in the pool as we speak.

FC: 1
pH: 8.5
TA: 130
CH: 200
Temp: 84
CSI: 1.08

In the pic, you will see tracks made by my vacuum. These tracks were made on day 2 of my initial SLAM and have not disappeared. So that tells me is that me adding chlorine to the pool made some reaction with the debris to stain the surface. In other words, no staining took place until I started the SLAM.

Any help?

 

[JamesW]

Possibly copper staining. Try some ascorbic acid on a spot to see what happens. Jack's has some copper and scale remover that might work but it reportedly has side effects that reduce its value.

Did you use calcium hypochlorite?

 

[tangouniform]

Possibly copper staining. Try some ascorbic acid on a spot to see what happens. Jack's has some copper and scale remover that might work but it reportedly has side effects that reduce its value.

Did you use calcium hypochlorite?

Ascorbic acid = the Vitamin C tablet? I tried one and it did nothing. Of course this was an over the counter Vitamin C tablet that was orange in color, but it was all we had in the house. Does that make a difference?

Don't know what calcium hypochlorite is so I'm going to say no there.

 

[Divin Dave]

calcium hypochlorite is a form of powdered chlorine which uses calcium as the chlorine stabilizer.

Do you have a chlorine puck? If you do, vigorously scrub the stain for a few minutes to see if it removes or lighten the stain. If it does, the stain is orgainic and can be removed by elevating the FC to SLAM level for an extended period of time. The chlorine will eventually remove the stain. It may take a while though.

 

[tangouniform]

calcium hypochlorite is a form of powdered chlorine which uses calcium as the chlorine stabilizer.

Do you have a chlorine puck? If you do, vigorously scrub the stain for a few minutes to see if it removes or lighten the stain. If it does, the stain is orgainic and can be removed by elevating the FC to SLAM level for an extended period of time. The chlorine will eventually remove the stain. It may take a while though.

The only chlorine in my pool is via household bleach.

I have tried the chlorine puck directly on the stains with no improvement.

 

[JamesW]

Looks like copper to me. Copper can be very difficult to impossible to remove. The turquoise color with black and grey patches is very common with copper.

Turquoise is actually a copper compound.

Acid washing might be the only reliable way to get good resolution. However, that will cause the surface to be very rough.

Do you know if copper is in the water?

One of the things that happen with copper staining is that the plaster gradually turns greenish/turquoise with one type of copper compound.

Since it’s gradual and usually uniform, it can go unnoticed. Then something causes the copper to change (high pH and/or high chlorine) and the turquoise turns into black and grey stains that are much more noticeable.

 

[tangouniform]

I have read about the copper stains, but there's no sort of blue/green tint to these stains. They are 100% brown.

 

[JamesW]

Maybe the picture color is not rendering well for me. If it’s brown, it could be iron, but the ascorbic should have had an effect.

The other possibility is scale. With your high pH and CSI, scaling is likely. Get the pH down and brush as much as possible.

Adding a sequestrant should help as well.

Do the stains feel rough?

Note that scale is usually white but it can be other colors if dirt, sand or other debris get incorporated into the scale.

The general green color does look like copper to me. Is that the original color of the plaster?

 

[tangouniform]

The actual color of the plaster is white. The green/bluish tint is just the water color at dusk with low light. The water is 100% clear and the stains are all brown in color. I'll try to hop in and get a feel for the stains tomorrow, but generally the whole surface is rough so I don't know if I'll be able to delineate the stain from the rest of the surface.

 

[JamesW]

Ok, I think that it's probably scale. I would get the pH down to 7.2 and keep it there until the scale clears. I would also get the TA down to about 60. Brush at least 1 to 2 x daily. Maybe get a good 18" wide stainless steel pool brush.

How are you getting a ph of 8.5?

 

[pooldv]

More about calcium scale here, Pool School - Calcium Scaling

 

[tangouniform]

Would there be any harm in doing the ascorbic acid treatment without knowing this is an iron problem? I have no issue spending less than $50 for a chance of it clearing up the stains.

 

[JamesW]

I would test a small spot before doing a full treatment. If it doesn’t respond, the ascorbic probably won’t work.

 

[tangouniform]

Just an update. I went on a 5-day trip and dumped about 80oz of muriadic acid in before I left to lower the pH to see if anything could clear up while I was gone. I left the pump on low the entire time. I got back last night and test my water, and it read at 8.2 pH. I have no water feature or anything else that could be aerating the water. How is the pH staying this high? I think this is the root of my problem.

Edit: I will add that we got about an inch of rain in the 5 days I was gone. Would this be enough alone to cause the pH to stay this high?

 

[pooldv]

What did you lower PH to? What is your TA? Do you have an autofill? What is the PH and TA of your fill water?

 

[JamesW]

The pH is staying high because your TA (Total Alkalinity) is too high.

Pool School - Lower Total Alkalinity

I would get the pH down to 7.2 and keep it there until the scale clears. I would also get the TA down to about 60. Brush at least 1 to 2 x daily.

Maybe get a good 18" wide stainless steel pool brush.

 

[YippeeSkippy]

When you covered the pool up before deploying did you by chance add any algaecide products to the water?

 

[tangouniform]

When you covered the pool up before deploying did you by chance add any algaecide products to the water?

Negative.

I bought 4gal of MA and I'm going to attempt the No Drain Acid Wash. My daughter is having a b-day party on Saturday so I'm trying to clear this up in the next few days if possible.

Even though the stains feel same to the touch as the rest of the pool, I'm convinced this is scaling due to the high pH of my pool year round.

 

[tangouniform]

Tried a bigger sock full of Vitamin C on my top step. The area around the sock turned white, but the area that the sock was actually resting on turned purple. Anyone seen this?

 

[JamesW]

I suspect that you have multiple things going on at the same time. Probably copper, iron and scale.