Algae in the winter?

[Nod]

So I decided to go cover free this winter and some stuff has gotten in the pool, but I have fished most of it out. Well this past couple of weeks, it looks like alge took over. It is a nice shade of green. The temp has been in the 50's. I didn't think algae could grow in this climate?

Should I treat now or wait til spring?

 

[chem geek]

Poconos (Al) on The Pool Forum showed pictures of algae growing under ice. Algae can grow in cold water, but does so more slowly.

If you treat it now, it may be easier. All you have to do to prevent it is to maintain chorine in the water over the winter. So long as the water doesn't freeze, this is pretty easy to do since chlorine usage in cold water is very low at < 1 ppm FC per week if the water is not exposed to sunlight. You could also try using PolyQuat 60 algaecide upon closing next time, though I don't know how long it will last in the water -- if there's no chlorine then it will last longer and if there is minimal filtering it will last longer (it's a clarifier so will get filtered out if there's stuff to filter in the pool). See this Pool School article for more info.

Richard

 

[budster]

I second the geek. 8)

 

[duraleigh]

Yep, I get "green pool" here in North Carolina in the winter, too. Chem geek has got it covered!

 

[Nod]

Thanks everyone - I hit it with 4 jugs of bleach - its clear now - I hadn't put anything in it since november thinking that algae wouldn't grow, so why bother, but now i know!

 

[aaronp]

So long as the water doesn't freeze,

So, what happens if the water DOES freeze?
I was thinking about chipping a hole in my skating rink (joke, not actually skating)
and getting a head start on the algae while it is somewhat dormant.
I was hoping the ice cap might prevent loss of chlorine, maybe?

My pool is in swamp-for-more-than-a-year mode.

Will the bleach diffuse itself enough without the pump? (which is winterized)

 

[chem geek]

I just meant that it's easy to add chlorine to the water when it's not frozen. If you don't mind chipping/boring a hole to get access to the water, that's fine, but if you add chlorine and there is no circulation, it can settle to the bottom of the pool as its denser than water until thoroughly mixed. If you have a vinyl pool, that might be a problem. With a plaster pool, it might be OK so long as you don't dump a bunch in quickly. If there is any way for you to very slowly pour some in and then use something to try and stir the water, then that would be good.

However, don't expect the chlorine to spread to other areas of the pool so you could get algae in those areas. Multiple chip/bore holes would be needed -- sounds like a lot of work which is why I made the "when it's not frozen" comment.

So long as you treat your pool as soon as the ice thaws and before the water warms up, then you can easily kill any algae that has formed. That's what most people do as part of spring opening. Getting rid of a small amount of algae is no big deal.

Richard

 

[Swimgirl]

I put some polyquat 60 in my pool about the end of November, raised the Chlorine to shock level, and haven't done anything with it since except run the pump on freezing nights and rinsed out my filter once. I have a solar cover on it, and the temperature stays around 50 degrees. When I peeked under the cover a couple of days ago there wasn't any algae growing. I'm thinking that's probably the polyquat helping out.