Have some kind of yellow algae (?)

[march2012]

Was away for a month and my pool turned green in the last week we were away. We have a saltwater system but with the texas heat at 105+ it wasnt able to keep up on the 60% setting that I set it to before I left.

We got home tuesday night and so started slamming the pool on this last wednesday. My CYA is around 70 so I used 28ppm of FC via bleach.

I poured all the FC into the hot tub which cleared the hot tub overnight then it took another day for the rest of the pool to clear.

Unfortunately after all the green was cleared there were yellow stains on the pool surface. Brushing them doesnt do anything.

I thought it might be mustard algae, but I thought mustard algae was more powdery.

I did another night of slamming until the pool passed the OCLT and then switched to mustard algae protocol. Last night I bumped up the FC to 60 (by accident) but it didnt have any effect on the yellow. I was thinking it might be slightly lighter, but my wife says no.

The water is very clear

Here is a picture.

 

[Rancho Cost-a-Lotta]

I haven't seen yellow staining like that before. Have you used any algaecides? I'll give you a bump to get more eyes on your post.

 

[march2012]

I haven't seen yellow staining like that before. Have you used any algaecides? I'll give you a bump to get more eyes on your post.

Thanks. I've only ever added bleach muriatic acid, cya, trichlor and salt

 

[JamesW]

Probably iron.

Put some vitamin C on a spot.

 

[JamesW]

Stain ID Kit | Jacks Magic

jacksmagic.com

It looks like you might also have copper stains.

Try a stain ID kit.

 

[march2012]

I suspect you guys are right, I plan to test with vitamin c. The ph got high while we were gone so I think any metal came out of solution.

 

[march2012]

Ok I put crushed vitamin C onto one of the stains and the entire area is now stained black. Any suggestions? The vitamin c test was apparently a terrible idea.

 

[JamesW]

Probably high copper levels.

What copper has been added to the pool?

Can you show the whole pool and system?

Do you have and ionizer or a mineral cartridge?

Have you used copper or silver algaecide?

Can you remove the filter cartridges and show them before and after cleaning?

Try the stain ID kit.

Stain ID Kit | Jacks Magic

jacksmagic.com

 

[JamesW]

Maybe the tab feeder is back feeding chlorine into the heater.

Are you feeding something else through the tab feeder?

If yes, what?

Is the peristaltic pump for acid or chlorine?

 

[JamesW]

The color of your plaster is very close to the first type of copper stains, which makes diagnosis difficult.

Copper stains usually start out blue or turquoise and then turn black as the copper oxidizes.

 

[JamesW]

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Blue green stains

I have a plaster pool and spa that both were initially the same color. The spa developed a blue green stain. I am in the middle of slamming it because I assumed this was an algae stain. I read more about it and tried both the trichlor pucks test and the vitamin c test. Neither removed or...

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Black Algae and High Copper

I used the Copper Ionizer and did not notice copper went high 1.5. Pool wall and bottom is black color now. It looks like black Black Algae. Please advice how to control the Copper or black Algae. I used No Metal from Leslie pool and cleaned the filters, no luck.

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[JamesW]

The vitamin c test was apparently a terrible idea.

I don’t agree that it was a bad idea because it has provided important diagnostic information.

It has provided information that indicates that you have something in the water that needs to be addressed before it becomes a much larger problem.

As you can see from the pictures posted, the copper can go from turquoise to black as the oxidation state of the copper gets altered.

I recommend that you have the water tested for copper to see where you are at and then plan to address the issue if it comes back as high.

The stain ID kit is also recommended to see what that shows.