Re: How long should it take to clear black algea
Ben, Hi - thanks for the info. Can you tell me what causes ph to drop? Mine went from about 7.4(Sunday) to 7.0 today?
Also, I forgot to ask you, have you ever heard of this "shallow water blackout,", that killed them?
Here is the link for the pool story. Thanks
http://www.nypost.com/p/news/local/s...Aqwu1yYESlH4kK
Re: How long should it take to clear black algea
Yes, I've heard of it. I've even seen it -- and smelled the vomit when the kid barfed while the lifeguard (who'd been inattentive) did rescue breathing.
The most common scenario is a group of middle school boys doing breath-holders . . . and one of the boys passing out while trying to avoid embarrassment.
Re: How long should it take to clear black algea
Wow, very scary. I have a 6 year old son. I will make sure he knows this. My wife is the principal of a k-12 school. I will tell her. She has a newsletter, parents need to know about this. Any thought on why my PH is dropping? I do have another question. With regards to the health/safe/clean of a pool, does a high CYA need more cl to keep it safe? Or is the cya number only relevant for usage and stability?.
Re: Shallow water blackout
Shallow water blackout is a common cause of drowning. Lifeguards should be, and sometimes are, trained to be on the lookout for activities which leads to this event.
As I understand it, there are two common scenarios that often precede this. The first -- swimmers or others training -- is the one in the article you referred to. Many elite senior USS swimmers do "breath-holders". My 16 year old son does. The second -- elementary or middle school boys competing in breath holding or underwater swims -- was involved in the drowning I saw. (BTW, that boy did recover.)
In the first case, those training should NEVER do breath holders without someone 'guarding' attentively.
In the second, parents and lifeguards need to watch out for competition with unequally skilled kids. Male ego gets involved, and the drowning victim is often the weaker, and embarrassed about it, swimmer.
In BOTH cases, swimmers need to be encouraged (or with boys) prevented from hyper-ventilation. As I understand it, 1 or 2 deep breaths is fine: more are not!