Semi-transparent patches floating on water

[Jjnol]

That's a relief. I have encountered some pretty horrible recommendations over the years by 'chemists' who were not water treatment specialists, so you really scared me. For what it's worth, mercury contamination would not necessarily have been irritating.

On the other hand, copper stains pools. If that's a concern (it doesn't bother everyone), you'll need to be cautious as you add chlorine.

Regarding your original comments:

+ CYA is one of the most critical measurements on an outdoor pool. It's very difficult to manage an outdoor pool correctly without knowing this. Most algae problems come because people do not understand that chlorine levels have to be determined based on your CYA level. Of course, some people get lucky, and do the right thing by accident. If you are naturally lucky, that's always an option.

+ Low hardness does not cause 'floaters'.

+ Dichlor and trichlor are 2 different chemicals. Both are forms of stabilized chlorine, but have somewhat different properties. The percentages you list don't correspond to undiluted products, so I'm guessing you are buying one of the diluted forms of those products. Dilutants can include borax (harmless or even helpful), magnesium sulfate (harmful to your pool), aluminum sulfate (mostly useless, but potentially harmful to concrete pools), copper sulfate (effective algaecide; effective staining agent) and so forth. You can check the "available chlorine %" to be sure. Trichlor should be 89% or higher available chlorine; dichlor should be either 56% or 61%.

+ Regarding the patches themselves, I have no idea. I can't recall ever seeing anything that would fit that description, but it doesn't sound like you could get a photograph of them. So I can't help with that.


Good luck!

Thanks so much. Very enlightening. So cyanic acid is in essence the 'stabilizer' factor I've seen in the test kits. Mine was on the high side a few days ago when my water level was to the 1/4 of skimmer level. I was almost going to add water but we had a day of flash flood weather and I had to drain the pool from above the skimmer to 3/4 and now stabilizer looks OK. If anything I have to work at keeping the chlorine level up. Not seen the lock-in. I've never seen algae.

The previous owner was telling me he only used the copper based shock in the winter because it works very differently to create free chlorine then the other treatments. And seriously other then these little filmy patches that I've seen floating on the surface, appearance and chemistry has never been seriously out of whack since I got it cleaned up after winter.

BTW, this evening I looked and they were gone. All sucked into the skimmer. I shocked it last night.

If I can get the right light and angle I'll use the macro lens on my digital SLR to see if I can get a photo of the translucent floaters as they get sucked into the skimmer. They do come and go. It may just be some form of pollen for all I know.

It's good to know it's not the hardness. I'm not going to play with adding calcium as long as it won't cause a problem for my vinyl surfaces. Someone told me having too soft water would dry out my vinyl which did not make sense to me.

The stuff I use for shock come in 1lb packets from PoolTime and seem to work well.

And concerning the CYA it's my understanding that the tablets I put in my floating dispenser may actually be adding that to the pool. I'll check and if so try not to over do that. I thought for a while the more chlorine the better -- clearly not so.

And again thanks for the helpful reply.

Justin