How deadly is this stuff, and how much should I worry?

J

JoseJones

#1
We recently inherited a pool when we bought our home in Dec. The pool is a wreck and we decided we'd rehab it this summer and weren't going to do anything with it until then, but the weather got nice and well, it beckoned us to come and frolic it all its Ol' Swimming Hole Glory.

Long story short, now that the levels are nice and the water is clear I see these black spots in various areas. On my usual (now daily) trip to the pool store, I ask the guy about getting rid of this and he nonchalantly hands me some Black Algae Killer. He's waving this thing around, I'm waving it around. I'm almost tempted to let me daughters hold it and suck on the bottle. Because the guy is not concern, I'm not concerned. (You see where this is going, huh?)

No sooner than I get home I read the instructions which basically says: If this touches your skin, you die! If you inhale this, you die! Burn your clothes after dispensing....

So, I get the picture. This is bad stuff. So, given its so bad, do I want my children swimming in it?

Sincerely,

Jose
A little freaked out pool owner
 

JasonLion

LifeTime Supporter
Platinum Supporter
TFP Expert
May 7, 2007
37,879
5
Silver Spring, MD
#2
Welcome to TFP!

Dealing with the concentrate and dealing with it once it has been mixed into the pool are totally different things. The concentrate is far more dangerous. Even concentrated it won't kill you right off or anything like that. As long as you follow the directions on the package about not swimming for some period of time or anything along those lines that they mention you will be safe enough.

On the other hand I am skeptical that it will actually work. Algicides rarely work and black algae is especially difficult to kill off.
 
J

JoseJones

#4
If it won't work, then what?

JasonLion said:
...On the other hand I am skeptical that it will actually work. Algicides rarely work and black algae is especially difficult to kill off.
So what should we do? Pretend it's part of the whole swimming hole motif? Or is there something more constructive?
 
J

JoseJones

#5
JCJR said:
...I am a little concerned about your daily trip to the pool store, just read those stickies and soon you will be going less frequent.
It's actually weekly. But that didn't have the dramatic effect I was looking for. All the levels are great. The pool store guys gave me an A+ for how quickly I caught on, but I always did well in Science...
 

257WbyMag

LifeTime Supporter
TFP Expert
Feb 23, 2008
5,061
0
Denton, TX
#6
To reduce pool store visits and clear your algae...

1. Read the stickies.

2. Get a good test kit (TF100 or Taylor K-2006) and trust YOUR results over the pool store's results

3. Bleach, bleach, and more bleach.

4. Seek advice on this forum when you are stuck and don't know what else to do.

Craig
 

JasonLion

LifeTime Supporter
Platinum Supporter
TFP Expert
May 7, 2007
37,879
5
Silver Spring, MD
#8
Some people have been able to kill black algae by letting a trichlor tablet sit on the black algae spot for a day or two. Others have had success with raising the FC level up to shock level and brushing the spots very frequently for a week or two. Other people just raise the day to day FC level, which keeps them from spreading and bleaches them out a bit but doesn't kill them, and live with it.

You might want to confirm that it really is black algae. A simple test is to rub a spot gently with a trichlor tablet for a minute. If the spot fades away and then comes back a couple of days latter it probably is black algae.
 

chem geek

LifeTime Supporter
TFP Expert
Mar 28, 2007
12,082
2
San Rafael, CA USA
#9
By the way, if it is black algae, it took a long time to develop from neglect of the pool, not maintaining sufficiently high Free Chlorine (FC) levels relative to Cyanuric Acid (CYA) levels. You "inherited" that problem, literally. So it will take time to get rid of that black algae, if that's what it is, but the approaches of high FC and brushing are key. Black algae has deep roots into the plaster which is why it takes longer to kill and why brushing is key since it breaks off the slimy surface layer exposing deeper layers to the high chlorine levels.

Richard
 
G
#10
I would be interested in knowing the ingredients. The two most common black algae treatments are sodium bromide and granular trichlor with copper sulfate being the third most common.
The most dangerous is probably the trichlor. However, this is also what chlorine tablets are made out of.

The most common form of algaecide in general are the linear quats. THESE are actually extremely toxic yet they are the most common ( and least effective, IMHO ) form of algaecide sold.
 
J

JoseJones

#12
waterbear said:
I would be interested in knowing the ingredients. The two most common black algae treatments are sodium bromide and granular trichlor with copper sulfate being the third most common.
The most dangerous is probably the trichlor. However, this is also what chlorine tablets are made out of.

The most common form of algaecide in general are the linear quats. THESE are actually extremely toxic yet they are the most common ( and least effective, IMHO ) form of algaecide sold.
Here's about the good stuff in the bottle.
http://www.pesticideinfo.org/Detail_Pro ... _NR=042291

copper 3%
dimethylbenzyl ammonium chloride 26.3%

thank you to all with your help!
 
G
#13
JoseJones said:
waterbear said:
Here's about the good stuff in the bottle.
http://www.pesticideinfo.org/Detail_Pro ... _NR=042291

copper 3%

Most likely copper sulfate

dimethylbenzyl ammonium chloride 26.3%

a linear quaternary conmpound

thank you to all with your help!
This is your standard "combo" algaecide. Remember that ANY pool chemical can be considered a poison, even the baking soda used to raise total alkalinity or the salt used wth a salt water generator, in a large enough dose. Some pool chemicals are decidedly dangerous, such as muriatic acid and clorine. Some are relatively innocuous, such as baking soda, borax, and salt.

As far as copper goes, in small quantities it's a necessary nutrient and it is actually used in water purification sometimes to make water SAFE to drink. In large quantities it is toxic. It is much more toxic to algae and lower invertibrates than it is to humans, however.

As far as the dimethylbenzyl ammonium chloride, this and the related linear quats are used in MANY household product including:
household disinfectants
hair prducts such as mousse and hair conditioners (creme rinse), since it softens and detangles the hair, and hair tonics.
medicated soaps
specialty cleaning and sanitation products
toilet bowl cleaners

Bottom line is this, pool chemicals ARE dangerous if not respected but nothing to fear if used properly and with common sense.

The bad news is this is NOT the first choice of algaecide for killing black algae. You will have much better results with a LOT of chlorine, a LOT of brushing, and a LOT of patience. If you CYA is very high then sodium bromide and a LOT of chlorine would be the most effective way. If you have only a few spots AND your stabilizer is not very high then granular trichlor is effective.