Winter Green

[caseyrichards]

Hi everyone. How do I solve green pool water in the winter? I leave it open year round even though it is not in use just because I like the water feature of a blue swimming pool. I was under the impression algae blooms that take over the whole pool are rare in cold temperatures yet here we are. And because chlorine is less effective below 65 degrees I have already tried quadruple shocking with liquid chlorine bottles and adding a clarifier plus algaecide. The chlorine should still be working even if it is a slower reaction due to the cold but again I am here because it is still green. So I am at a loss. Any suggestions to restore it back to blue right now during winter rather than wait for warmer temperatures in spring/summer?

 

[Newdude]

I have already tried quadruple shocking with liquid chlorine bottles and adding a clarifier plus algaecide

Have you been poolstored ? Possibly re-poolstored ? None of that is TFPC. What happened ?

Have a refresher :
SLAM Process

Follow it to a T and it works. Ask away at any point and we'll fill in any blanks. Post progress and we'll cheer you on.

 

[PoolStored]

Have you been poolstored ?

Somebody call me?

Looks like @Newdude has you covered. Follow the SLAM process.....

 

[caseyrichards]

I understand SLAM. What I am having trouble understanding is the reason for green algae in freezing temperatures. And I am questioning the chlorine’s actual effectiveness in these low temps as well. So before spending more money on chlorine to bring up to SLAM levels is this even possible right now or do I just need to leave as is and wait until pool season?

 

[Newdude]

What was the water temp when it turned green ?

What's the CYA ? (Warm the sample to room temp when you test)

What's the date code on the bleach?

 

[TinFoilHat]

Did someone fool you and dump green dye in it? "Shhh, let's mess with Casey and see how he freaks out when we put this dye in his pool."

 

[sande005]

30+ years dealing with a pool here in the frozen north. It is always a race between getting the cover off before all the ice has left the pool and it then turns green. Several times I got it off, only to see it all turn green within a week at 40 degree temps. It is a myth that algae doesn't grow in cold water. It may not grow as fast as summer, but give it light and non-solid water, and it will grow.
Others with deeper chemistry knowledge can give the details, but the ability of CL to sanitize (ie - kill algae) is not a 1:1 relationship with temperature. It may be somewhat less speedy at lower temps, but it does still work. Says the guy that had to SLAM his above pool a few times with the temp around 40.

The good news, with the lower amount of daylight currently, you'll loose less CL via that, so your SLAM levels should hold better than they do in the summer.
As noted - test the water samples after warming to room temp - that chemical reaction CAN be greatly effected by temp.

 

[caseyrichards]

Thank you all for the info. I will test and follow up.

 

[sande005]

There have been too many early springs where I seem to be in the business of just moving color. Getting the green out of the pool, but at the same time trying to get green into the lawn.

 

[Bperry]

I understand SLAM. What I am having trouble understanding is the reason for green algae in freezing temperatures. And I am questioning the chlorine’s actual effectiveness in these low temps as well. So before spending more money on chlorine to bring up to SLAM levels is this even possible right now or do I just need to leave as is and wait until pool season?

The water is way above freezing temperature, That’s why. Chlorine is just as effective at cold temp and summer temps.

 

[Jimrahbe]

Casey,

My pool also stays open all year..

But, I keep my pool chemistry the same year round. I slack off on how often I test, but I still keep my FC up all year long.

Since I have a SWCG and it shuts off when the water temp gets to about 52 degrees, I use liquid chlorine in the winter.. It does not take much during the winter months.

This takes me about 15 minutes a week.. Not a lot of effort...

Thanks,

Jim R.