Black Algae

[sigs]

Folks, I woke up this morning to a nightmare. See the attached pictures. In summary, I have black algae that has seemingly appeared overnight. It is on all flat surfaces and even the waterline. The pictures doesn't really show how bad it is and scrubbing doesn't remove much of it. 2 days ago my pH=7.4. This morning pH=8.0, which is not too alarming but does need treatment I know. Strange thing is that everywhere I threw the Clorox pH Down, it immediately disappeared. I am perplexed as to what my next move is as opposed to scrubbing all surfaces with the pH Down (see spa picture). Got to be a better alternative. The pool and spa is fiberglass so there is no real area where black algae can attach. That said, for the last few years I had previously posted about potential calcium build up (white film which only comes off if you scrub it furiously). I checked everything and the readings are below.
ANY HELP WOULD BE GREATLY APPRECIATED!!!!

FC=16
CC=1
TC=17
CH=275
TA=80
pH=8.0
CYA=80
Salt=3150

Thanks
Sig

 

[sigs]

Also, it appears that the algae has attached everywhere that the "light" or potential calcium buildup is.

 

[PoolStored]

Black algae requires long term under chlorination. Something else is going on...

@JoyfulNoise @JamesW @ajw22

 

[ajw22]

Give us a full list of the chemicals you have used in the pool.

Acid making the black spots disappear indicates it is metal staining.

I don't see how you chlorinate your pool listed in your signature.

 

[JoyfulNoise]

pH Down, which is dry acid, and also something you should not be using to adjust pH, will not remove algae. As @ajw22 states, sounds more like a metal scaling problem.

 

[JamesW]

Probably copper stains.

 

[PoolStored]

Probably copper stains.

might also be silver staining...

Will be interesting to see what the OP has added recently.

 

[JamesW]

might also be silver staining...

The brown is silver, the turquoise is copper, the black is also probably copper that has been oxidizer further than the turquoise copper.

 

[JamesW]

salt film

Folks, my wife and I have a substantial issue with our fiberglass pool and spa. beginning early last year, the sensor on our salt cell went bad and long story short, we ended up over salt saturating the pool. 6000PPM, yep got that high. Anyway, we ended up getting everything under control...

www.troublefreepool.com

 

[sigs]

Black algae requires long term under chlorination. Something else is going on...

@JoyfulNoise @JamesW @ajw22

Thanks, I did replace my salt cell about 6 weeks ago and have been struggling to find the right setting. Currently set to 20%. Is there a chemical I can add to kill it? Does it happen often to fiberglass pools? Is it really black algae? Why does the Clorox pH Down kill it immediately? Should I scrub all surfaces with the pH Down? Will it damage the gel coat? Why would this happen with the chlorine level so high if it is a symptom of under chlorination?
Only other change was a new Proteus DX5i three days ago...

Thanks
Sig

 

[JamesW]

Probably copper stains.

 

[JamesW]

Drop some vitamin C on a spot.

What copper is in the water?

 

[sigs]

No offense but "Something else is going on" really doesn't help much. I REALLY appreciate the reply but have read why black algae appears but my water is crystal clear with this exception. I did not post this before checking all chemical level. Thought maybe the new salt cell went out but is not the case. Working perfect! Except for the pH being a little high, all chemicals are within acceptable ranges. Seriously, 2 days ago it was perfect! In full panic mode at this point! HELP!!!

 

[JamesW]

It is NOT black algae.

It is probably copper stains.

Try to relax and read the responses to your post.

 

[sigs]

Drop some vitamin C on a spot.

What copper is in the water?

Not copper. Vitamin C does nothing. Does not remove the "black".

Any other suggestions?

 

[sigs]

Give us a full list of the chemicals you have used in the pool.

Acid making the black spots disappear indicates it is metal staining.

I don't see how you chlorinate your pool listed in your signature.

FC=16
CC=1
TC=17
CH=275
TA=80
pH=8.0
CYA=80
Salt=3150

Acid does not affect it. I have one of these: https://www.amazon.com/Purity-Pool-OS-Stain-Remover/dp/B004VLB3VE/ref=sr_1_1?sr=8-1 and use it to remove stains on the bottom using muratic acid and works great on organic stains. Muratic acid does nothing to the black.

I have a salt system. Pentair IC40

Thanks
Sig

 

[sigs]

It is NOT black algae.

It is probably copper stains.

Try to relax and read the responses to your post.

Taking a deep breath.
Sorry everyone.
I put some of the Clorox pH Down in my muratic acid applicator and the black comes off with a little patience. However, the prospect of doing this on the entire pool and spa makes me want to slice my wrists

Thanks
Sig

 

[mknauss]

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

That implies it is copper. Read the above. Also Copper in Pool Water - Further Reading

Have you used copper based algaecides? You show heaters, have you used trichlor tablets in a chlorinating device or put them in the skimmer?

 

[sigs]

FC=16
CC=1
TC=17
CH=275
TA=80
pH=8.0
CYA=80
Salt=3150

Acid does not affect it. I have one of these: Amazon.com and use it to remove stains on the bottom using muratic acid and works great on organic stains. Muratic acid does nothing to the black.

I have a salt system. Pentair IC40

Thanks
Sig

Sorry, misread your question. I use:

Clorox pH Up
Clorox pH Down
Clorox Alkalinity Increaser
Clorox Chlorine Stabilizer
Eco Living Solutions, Calcium Chloride Pool Hardness Increaser
Muratic Acid
Baking soda
Vitamin C (for metal stains)
ADDED: Clorox Green Algae Eliminator2 (back in April)

Thanks
Sig

 

[sigs]

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

That implies it is copper. Read the above. Also Copper in Pool Water - Further Reading

Have you used copper based algaecides? You show heaters, have you used trichlor tablets in a chlorinating device or put them in the skimmer?

No algaecides except back in April when I opened the pool up. No, I have not used trichlor tablets and only use the salt cell for chlorinating. When my salt cell indicated it needed cleaning I swapped it with a new one I had, then cleaned the other (yes, I purchased a spare just for this reason). Then, I did add some liquid chlorine.