Help: I think my pool has cancer The dreaded Black Algae.

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G

GarlicCity

0
Jul 13, 2015
28
Gilroy/CA
Pool Size
16000
Surface
Plaster
Chlorine
Liquid Chlorine
Hello All,

I'm feeling a bit exhausted after my 1st SLAM to recover a 2 year neglected pool about 1 month ago. It was my fault as I was recovering from a medical issue and just let it go. The pool looked good after I followed the great advice on here. There were some stains at the deep end which looked like leaf/muck stains as they would not brush off even with a SS brush. OK, I can live with that as I can still enjoy my pool. There were some iron stains which I removed with an AA treatment more than 2 weeks ago. Thanks again to TFP. Now I am having a black algae problem. I tested it by scraping it off with my fingernail and spreading it onto a white paper, it was dark green :mad:. I have been keeping the FC at 5ppm since the SLAM. I also added PQ 60 before hand, bringing up the FC slowly after the AA treatment.

So here we go again. I'm ready to SLAM again if it's not a lost cause. Here are my numbers:

FC: 18
CC: 0.4
PH: 7.2
TA: 110
CH: 275
CYA: 30

Photo of suspected black algae

https://www.dropbox.com/s/q34n70pp3j5q1t5/2015-07-23_08-19-38_33.jpg?dl=0

My pool today after overnight SLAM. Pool was perfectly clear before start of slam.

https://www.dropbox.com/s/chbbjn7mj0ep5g3/2015-07-27_08-11-53_174.jpg?dl=0


TIA.

Roger
 
bobodaclown said:
Hello,
Here's how to handle Black Algae. Pool School - Black Algae

It's not so bad, I've got a couple of spots that I'm fighting also. Just try to keep up on it. Your stainless steel pool bush is your friend. :)
Click to expand...

I brushed it last night and I can still see it. I'm really scrubbing it hard and it still looks black. I'm going to pick up a smaller SS brush to increase the pressure. What I'm not sure about is the staining on the bottom at the deep end. You can see it on the second picture. I think I'll be looking like Popeye after this is over. Looks like I can back off the high FC when the water clears. I'm going to try and dive down and get a sample off the bottom. I hope the test is negative.
 
It looks like black algae to me, too. You cannot get rid of it overnight. It got there after a long period of neglect and it will take a long period to get rid of it.

Keep you chlorine high and brush daily. You are uncovering it and exposing it to the chlorine. Your patience and steady brushing will eventually get rid of it.
 
duraleigh said:
It looks like black algae to me, too. You cannot get rid of it overnight. It got there after a long period of neglect and it will take a long period to get rid of it.

Keep you chlorine high and brush daily. You are uncovering it and exposing it to the chlorine. Your patience and steady brushing will eventually get rid of it.
Click to expand...

When I brush, should I try to get all of the black off? This is my first rodeo and I'm not sure when enough brushing is enough for the current session. Should I keep up the mustard level shock or the lower green algae shock? Thanks all for the replies.
 
one quick question - I see your light is out of the pool - great to have it out to be sure the niche is clean - could algae stay active on the back of the light while it is out of the water and come back when it is put back in later? should the light stay in the water during a SLAM?
 
bkfamily1 said:
one quick question - I see your light is out of the pool - great to have it out to be sure the niche is clean - could algae stay active on the back of the light while it is out of the water and come back when it is put back in later? should the light stay in the water during a SLAM?
Click to expand...

My thinking on that one was to leave it out so I can scrub in there during the SLAM then take it apart and clean the heck out of it while it is out and soak it in a 5 gallon bucket with high levels of FC. I will put it back in when I'm sure I've won the battle. Seems like a good idea, but I'm definitely not an expert. If I'm doing something incorrectly, please call me on it. Thank you.
 
garlic - I am no expert either, so take what I say with a grain of salt - note that I was not suggesting you mount it back in the niche - I agree scrubbing in the niche during the SLAM is a good idea - I was suggesting leaving it out of the niche but hanging down in the pool so any algae on the light is also killed during the SLAM
 
bkfamily1 said:
garlic - I am no expert either, so take what I say with a grain of salt - note that I was not suggesting you mount it back in the niche - I agree scrubbing in the niche during the SLAM is a good idea - I was suggesting leaving it out of the niche but hanging down in the pool so any algae on the light is also killed during the SLAM
Click to expand...

No offense taken or given, I was just explaining what I had planned. I think your idea may work better. It would probably be difficult to maintain the high FC in the bucket. I'm not really looking forward to all the scrubbing, but I'll do what I need to do. I appreciate your responses, please keep them coming.

Thank you.

Roger
 

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Update: +36hrs

Numbers:

FC: 14 in AM added 1 gallon Cl to push it up during the heavy sun.
CC: 0.2

Approximate same location as picture #1 from original post:

https://www.dropbox.com/s/4uqhr1ebqazj2fa/2015-07-28 BA 36hrs 1.jpg?dl=0

Pool as it is now, a little less green tint. This is after brushing:

https://www.dropbox.com/s/554gnvmt10o3m1r/2015-07-28 36hrs pool 1.jpg?dl=0

This is what I'm calling Black Algae Ash. Looks like charcoal rubbed on surface. Not sure if this is a stain or active BA?

https://www.dropbox.com/s/y6qrgu822b5298f/2015-07-28 BA 36hrs 2.jpg?dl=0

I'm brushing vigorously in the morning and when I get home from work. It's a good workout. :)

I'm no expert either, maybe you should vacuum and clean your filter?
Click to expand...

Filter is clean and my little friend (Pool robot) cleans/vacuums every day.

Looking up if I can get a replacement gasket for pool light before I risk taking it apart.

Here is a pic of the pool light. Not sure if that's calcium scale or etching, but wow. CLR?

https://www.dropbox.com/s/yqcdodk2r0vbv1a/2015-07-28 Light Fix 2.jpg?dl=0

Thank you all for your replies/help.

Roger
 
Update +60 hrs for the sake of others who may encounter this enemy (BA).

Numbers:

FC: 14.5 Added 1 gallon Liquid Cl
CC: 0.5 Using 10ml sample
CYA: 30

Brushing seems to be doing nothing to remove black "ash" in certain locations. See pic.

https://www.dropbox.com/s/elftc8ttdgpa6ku/2015-07-29 60 hrs pool 2.jpg?dl=0

Pool at +60 hrs

https://www.dropbox.com/s/p1hvxdxlmw5u4ee/2015-07-29 60 hrs pool.jpg?dl=0

Tried scrubbing some of the "black ash" off the side with trichlor puck: No difference.

Will keep up the battle.

Roger
 
Update +84 hrs.

My numbers:

FC: 10 Added 64oz, lowered target to 12ppm from 18ppm (mustard to green shock level).
CC: 0
PH: 7.7 (sample from previous day left out to dissipate high FC) Added MA to target of 7.2. Thought high PH causing iron to come out of solution.

Back-washed filter, lot of material came out.
Cleaned filter bag in my little friend (Dolphin Robot). Think of throwing it in the washer tonight. Filter bag that is. :)

I'm starting to think that I'm having multiple problems simultaneously. The black "ash" seems to be remaining if not growing. I think the plaster is so rough that the black material is in the pores and I can't scrub it out. I did have a iron stain problem before this, which was cured with a AA treatment.

https://www.dropbox.com/s/jwt7m8qf4n2s0pt/2015-07-30 Black Ash 1.jpg?dl=0

Here is the pool:

https://www.dropbox.com/s/fnq68nmddnxhdh5/2015-07-30 Pool 1.jpg?dl=0

I placed a TriChlor puck on some stains in the deep end for 15 minutes. The clear spot to the right it appears to have lightened the stain. Where the puck is currently in the pic did not lighten the stain. I'm a little confused as both stains look the same.

https://www.dropbox.com/s/k3p1yrrybsmy0im/2015-07-30 TriChlor Puck 6.jpg?dl=0

Any help is greatly appreciated.

Thanks for viewing,

Roger
 
You're making great progress.
Remember this part:
After several days to a week, if the above procedures are not resulting in noticeable improvement, you may have to add the following step to the removal repertoire (and it’s no picnic):
5. Rub a trichlor puck along all of the black algae-infested areas of the pool. This is best done immediately after brushing so the concentrated amount of chlorine can come in direct contact with the algae itself. Note that the acid in a trichlor puck can remove a thin layer of plaster which could result in slight discoloration. Therefore, this step should be performed only if steps 2-4 above are not resulting in a noticeable improvement after several days to a week.
Unfortunately, the procedure for removing black algae does not lend itself to a standard regimen where you can make rote statements like “Brush your pool X number of times a day”, or “Hold FC at X level for this long” and expect the algae to go away in X number of days. Because every pool and black algae outbreak is different, you may need to vary the steps above in terms of frequency, mix, and intensity based on observation of progress. And remember to pack your POP (Pool Owner’s Patience/Persistence).


Keep up the work.
 
bobodaclown said:
You're making great progress.
Remember this part:
After several days to a week, if the above procedures are not resulting in noticeable improvement, you may have to add the following step to the removal repertoire (and it’s no picnic):
5. Rub a trichlor puck along all of the black algae-infested areas of the pool. This is best done immediately after brushing so the concentrated amount of chlorine can come in direct contact with the algae itself. Note that the acid in a trichlor puck can remove a thin layer of plaster which could result in slight discoloration. Therefore, this step should be performed only if steps 2-4 above are not resulting in a noticeable improvement after several days to a week.
Unfortunately, the procedure for removing black algae does not lend itself to a standard regimen where you can make rote statements like “Brush your pool X number of times a day”, or “Hold FC at X level for this long” and expect the algae to go away in X number of days. Because every pool and black algae outbreak is different, you may need to vary the steps above in terms of frequency, mix, and intensity based on observation of progress. And remember to pack your POP (Pool Owner’s Patience/Persistence).


Keep up the work.
Click to expand...
Thanks for the words of encouragement. At least I'm getting a good workout. [emoji123]
 
Update +108hrs.

OCLT 25ml samples

9:00pm 7/30/2015


FC: 11.2
CC: 0.4

5:45 am 7/31/2015

FC: 10.0
CC: 0.4

Looks like I'm almost there. Once I reach it, I will continue for an additional week. Water is crystal clear. It looks like my iron stains are back, but I will deal with that when I know the Black Algae is defeated. Tip for others fighting this who also have metals, retain a water sample to be tested for PH the next day. Just leave it out and the FC will dissipate on it's own. Just test it for FC before you test for PH. I let my PH get up to 7.8 before I thought of doing this.

Pool at 108 hrs:

https://www.dropbox.com/s/kndeum62zebpl1l/2015-07-31 108hrs pool.jpg?dl=0

Black ash and/or iron stains?

https://www.dropbox.com/s/vgc4z9ki0hln9v8/2015-07-31 108hrs Black ash.jpg?dl=0

Thanks for viewing/responding.

Roger
 
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