Black Algae, Wire Brush, New Plaster

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kcindc said:
Could you try doing the OCLT after bringing your FC to SLAM level? Your pool is a little new to have a problem with black algae. I think you might have a problem with too low chlorine since your SWG is too small.
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The chlorine level was definitely too low! And I live five blocks from the Gulf of Mexico, so I suspect that combination is where the black algae came from.

Oh and by the way, this pool is used by a few small condos rented out by the night so the pump runs 24/7 and the water has never been cloudy.

As a first time pool owner, I trusted the PB to set it up properly, and I also trusted my housekeeper's husband to maintain the pool since he has a SWG pool. Unfortunately that turned out to be a bad idea and after getting far too much conflicting info from the PS via the husband, I'm having to take control. So here we are.

Please help me understand the importance of SLAM level at this point. The black algae page makes it seem as if FC 11 would be enough. I'm not trying to be difficult. I'm just trying to understand so thank you, thank you, thank you!!!.
 
First, knowing that you have a condo association pool is very important. Maintaining a condo pool is not the same as managing a private pool in your own back yard. We recommend that SWGs be 2 to 3 times bigger than the size of your pool when dealing with a private pool, but dealing with a condo pool and the liability associate with that is a little out of my league.

Algae can be present in large amounts before it is visible. A lot of people using that pool and maintaining it to be sanitary to keep people from getting sick will be difficult with such a small SWG alone.

I'll let someone with a little more experience chime in.
 
edjanowsky said:
Oh and by the way, this pool is used by a few small condos rented out by the night so the pump runs 24/7 and the water has never been cloudy.
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This adds a whole new spin on things. Please have your county/city inspector talk to you about the "rules" for a "public" use pool. They have rules about levels that do not pertain to a back yard, private use pool.

Let us know what they say and will will go from there.

The importance of a SLAM is to clear whatever is in the pool OUT before it takes over all of the way. BUT with it being public use.........We really need to have that addressed before moving forward.

Kim TFP MOD
 
Thanks Kim

The city referred me to the Nueces County Public Health District who governs public pools but without any zeal whatsoever unfortunately. They don't have any published guidelines and only referred me a pdf called Swimming Pool Water Chemistry by John D Puetz which wasn't very helpful.

My recent OCLT started at 3 and ended at 3 so I'm confused as to why a SLAM is needed. I'm not opposed, but rather curious.
 
Lets see if you can do something.........find some way to get some of that black stuff off and bring it up and out of the pool. Rub it on a white paper towel and let us see what it looks like.

The SLAM would be to get rid of the algae if that is what it is.

Can you also take a picture of the pool for us please?

Kim TFP MOD
 
kimkats said:
Lets see if you can do something.........find some way to get some of that black stuff off and bring it up and out of the pool. Rub it on a white paper towel and let us see what it looks like.

Kim TFP MOD
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Thank you again Kim!!! An aquaintance with a decade or so of pool cleaning experience got in the pool and originally diagnosed the black spots as "algae" which is what led me here. I then read the TFP Black Algae page and followed the instructions. I put the black smudge on white paper and smeared it green. I'm far from an expert but at this point I feel it's pretty safe to say I have black algae. If you feel a photo is still necessary, please let me know.

kimkats said:
The SLAM would be to get rid of the algae if that is what it is.
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Are you saying SLAM level chlorine is required even though the black algae page specifically states the following? And that SLAM (FC 28 to my CYA 70) would get rid of black algae without brushing?

  1. Brushing – its importance in removing black algae cannot be overstated. Brushing is required to rupture black algae’s protective barrier and prevent it from reforming. You will want a stainless steel brush to use on the plaster to knock off the algae’s protective coating so that the chlorine can attack the algae itself. Make sure you have the proper brush handy before proceeding to step 2.
  2. Maintain an FC level between the high end of the recommended “Normal” range and the Shock (SLAM) level according to your pool’s CYA level. For example, if your pool’s CYA is 40, the high end of the “Normal” FC range is 7 ppm and the Shock/SLAM level is 16 ppm. Maintain FC within this range until all signs of black algae are gone. Refer to either the PoolMath tool or the Chlorine/CYA Chart for the recommended FC ranges.
  3. Brush the black spots several times per day. You will have to brush more vigorously than you would during the normal weekly maintenance brushing.
  4. Look behind light fixtures, around ladders, and underneath removable steps for any black algae hiding in and around these areas. If any is found, it will need to be removed as well.

kimkats said:
Can you also take a picture of the pool for us please?
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Do you need a current picture showing that it's crystal clear, or can you use a picture from a couple weeks ago, or do you need one that shows the shape? I'm happy to oblige but not sure what you need.
 
Bad MOD, Bad! Must re-read first :( I had forgotten that the directions for black algae.

YOU are correct and I am wrong! Good call and thanks for helping me remember what is what.

I am looking for a pic of how it is now just so I can see how "bad" the black algae is and hoping that will help YOU see the progress as you get rid of it.

The best part about not having to do a SLAM is your guest can swim around you as you scrub the pool :roll:

Kim:kim:
 
A photo of the black algae would be hard to come by at this point as 99% has been brushed away. I had to look mighty hard yesterday to find a little to rerun the smear test.

- - - Updated - - -

My current question is regarding the appropriate FC level at this point. Is 11 or 12 sufficient to kill any brushed/exposed algae? I don't want to run any guests off as you suggest. Should I go higher?


This morning's readings are as follows.


FC 4 (even after adding a gallon of 12.5% bleach to yesterday's FC 3 reading)
CC .5
Ph 7.8


I've since added a quart of muratic (anticipating Ph 7.2) and one gallon of 12.5% bleach (anticipating FC 12).
 
No I bought the 5" steel brush attachment from the PS. My current question is regarding the appropriate FC level at this point. Is 11 or 12 sufficient to kill any brushed/exposed algae? I don't want to run any guests off as you suggest. Should I go higher?

- - - Updated - - -

This morning's reading is FC 4 even after adding a gallon of 12.5% bleach to yesterday's FC 3 reading. Does this mean my SWG - IC20 has zero chance of keeping up without supplementing chlorine????
 

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From the sounds of it you will have to supplement since your demand is so high. You got the "correct" one but we have found going bigger is better for this very reason. On top of your having the black algae........bigger would be better or supplement with chlorine. It will be interesting to see what happens when you get the last of the black algae out.

Until you do not see ANY black algae I would keep the FC on the higher side. Keep it just under SLAM level for you CYA so you do not have to do this again.

Kim:kim:
 
edjanowsky said:
No I bought the 5" steel brush attachment from the PS. My current question is regarding the appropriate FC level at this point. Is 11 or 12 sufficient to kill any brushed/exposed algae? I don't want to run any guests off as you suggest. Should I go higher?

- - - Updated - - -

This morning's reading is FC 4 even after adding a gallon of 12.5% bleach to yesterday's FC 3 reading. Does this mean my SWG - IC20 has zero chance of keeping up without supplementing chlorine????
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Your SWG can produce 0.75 pounds of chlorine a day when 24 hours a day at 100% output. You can plug that into pool math (16 oz in a pound 16*.75=12 oz of chlorine gas) and it says that is the equivalent of FC=6. Again, this is very low for the demands of a private pool in a someone's backyard and not enough to handle a public pool.

The bleach you are adding is not enough to raise FC and deal with the high demand of a public pool. You should be supplementing FC at least twice a day and you should never let the FC get below 5. Going below the minimum for your CYA is a health hazard and will allow regular algae to grow.

As stated earlier, it is safe to swim with FC levels at or below SLAM level for your CYA.
 
Thanks kcindc!

PS was out of bleach yesterday and until just now. FC was down to 6 last night after dark and 5.5 to 6 this morning even running the SWG all night. So I'm adding a gallon of 12.5% now and another in a few hours. There are guests in there now.

I guess in comparing last night's and this morning's FC, I should rerun the OCLT.
 
Last night the FC was 12.

This morning's readings are as follows.

FC 9.5
CC 0
Ph 7.6


I added 30oz of muratic (anticipating Ph 7.2) and one gallon of 12.5% bleach (anticipating FC 18). I clearly had overnight FC loss so it seems I need to raise the FC to SLAM but for how long?

I'm just not confident in my CYA but only because of my inexperience. I'll get some more R-0013 and try it again, though it sure looked like the dot disappeared at 70 at waist level with my back to the full sun.

I added one more gallon of 12.5% this morning.


This photo was taken yesterday afternoon.
View attachment 64179
 
For the CYA test you just GLANCE on at the dot. Do not "look for it. Just glance in and out a couple of times.

When you are.doing a OCLT you need to test about 15 mins after you add the chlorine to make sure of where your fc is.

Kim:kim:
 
You need to do your own CYA test. This is the test the pool store gets wrong the most. The reasons are many but we have seen it time and time again.....pool store=wrong CYA amounts. Please do you own CYA and let us know what YOU get when you GLANCE in the tube like I talked about above.

Kim:kim:
 

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