Algae and Ice?

[Floater]

So...decided to try the "no cover" this year and have had an exceptionally cold winter. Up to last week, we had a frozen pool, not sure how deep it was. The ice started melting and the water looked a little dirty to me under the ice...thought it might just be dust on top of the ice. Then as the ice really started disappearing, it showed green. I in my dumb wisdom thought that algae could not grow in water that was frozen or partially thawed. I'm telling you the water is still cold and there is still a layer of ice, but the green is all on the bottom and up the sides though water is still clear.

My problem is that my pump and all is dismantled and I know we are due for some more cold weather before the really big thaw. Am I just to sit and watch this thing get worse or should I break out the pump and have at it? I usually don't start the pump up until around May but then I've always had a cover on and never had this problem.

Thoughts?

Just to add, about two weeks ago, the water was completely clear so I know it was not a problem I closed with.

 

[benavidescj]

Yes, algae will grow under ice. Of course it grow slower when the water is cold, but it will certainly grow. It is up to you if you want to get rid of it. You will have to add clorine to shock level relative to your current CYA level using the procedures found in Pool School.

 

[Melt In The Sun]

With a winterized pool, you don't really have a choice but to leave it or open the pool for the year (like you said, it's a bit too early for that). Even if you killed all the algae you'd have no way of filtering it out.

 

[duraleigh]

I leave my pool open as well. I always have a little clean up battle with algae when I get things cranked up in the Spring but adequate levels of chlorine (holding Cl at shock value until the pool clears) almost always fixes it in just a few days.

I've heard there are more than 7,000 species of algae. Probably VERY few of them can grow in temps below 50 but those very few seem to enjoy finding my pool. :lol:

 

[Floater]

Thank you all for clearing that up for me...geez, I think I will wait but it will drive me crazy. Now I just want to add the ugly cover so I don't have to look at it.

Thanks to this website and the BBB method I have found here, this is the first time in four years I can say I have to cure an algae bloom......but I will succeed and Dave....looks to be I will be buying some more kit refills soon

Thanks again!

 

[chem geek]

If you want to help prevent algae growth during the winter, you can close the pool by using some PolyQuat 60 algaecide as mentioned in Closing an In Ground Pool. Did you do that? Or you can use 50 ppm Borates in the pool though that's a rather permanent decision (only removed by a water change or significant dilution). Closing only after the water gets quite cold also helps as the chlorine or PolyQuat that is left lasts a lot longer at that point.

 

[Floater]

If you want to help prevent algae growth during the winter, you can close the pool by using some PolyQuat 60 algaecide as mentioned in Closing an In Ground Pool. Did you do that?

No, I did not look into any additional ways to close the pool other than bringing my pool up to schock level about the time the water hit 60 degrees because I honestly thought algae did not grow in anything much less than that. Again, my water temperature hasn't changed from when it was clear so the bloom was a complete "schock" to me! But... now I know better and will take steps regarding that if I do this type of closing again.

I have learned a lesson here today folks!

 

[chem geek]

Even the PolyQuat may not be enough. Probably more important is to close the pool as late as possible so that the water temperature is as cold as possible. Even with a water temperature of 50ºF in my own pool that I don't need to close over the winter, I find that the FC still drops by 1 ppm about every 2 weeks (with an opaque pool cover) so a shock might not last through the winter. At 60ºF, however, the chlorine might have dropped faster, perhaps at 1 ppm FC per week (assuming no exposure to sunlight -- i.e. using an opaque cover). PolyQuat will also break down from chlorine, though at colder temps that can take a while. So closing as late as possible and opening as early as possible is the safest bet since it has whatever you do upon closing much more likely to last through the winter.

 

[Melt In The Sun]

Richard,
Can you realistically expect to not have algae if you don't cover, as in the OP's case? I suppose if you added manually and brushed you could make it, but with no filtration all winter it seems like it'd be a mess no matter what.

 

[JasonLion]

If you winterize and don't cover the pool the chances are good that you will get at least a little algae. There are various ways to tilt the odds in favor of less algae, but it is tricky to reliably not have any algae. Generally you can minimize algae in this situation by closing very late, opening very early, using polyquat, and adding a little chlorine manually every couple of weeks.

 

[chem geek]

Yeah, not having a cover pretty much means the chlorine isn't going to last in spite of the colder temperatures. The UV from sunlight will still break down chlorine at roughly the same rate even at colder water temps. So a shock isn't going to last very long -- perhaps a week or two depending on the shock level and the CYA level.

Polyquat won't be affected by sunlight which is the main reason for using it but it's not a guarantee and doesn't last more than a few weeks at warmer temps, but should last longer at colder temps. It's also a clarifier so will get caught in the filter if your pool isn't clean, but then that means PolyQuat isn't in the bulk water anymore if you're still filtering. So using PolyQuat a day or so before you turn off your pump for closing at least has it stay in the bulk pool water. I don't know how long it lasts, but if the water is colder then maybe it'll help for several months, maybe more.

 

[Floater]

Soooo just thought I'd let all know that the algae ice monster is GONE from my pool. Started on Saturday...done by Tuesday (technically Monday am). Just letting the filter run through the rest of the week to help getting it back to sparkling. Really is a painless process as long as you know what you're doing and can stay on top of it. A big THANKS to TFP and its members for all the vast knowledge I have learned from this site. Kudo's to you [attachment=2:2ltzqn2o]DAY 1.JPG[/attachment:2ltzqn2o][attachment=1:2ltzqn2o]DAY 2.JPG[/attachment:2ltzqn2o][attachment=0:2ltzqn2o]DAY 3.JPG[/attachment:2ltzqn2o]

 

[chem geek]

Nice job! Yes, once you know how to properly shock a pool, clearing it of algae isn't so painful unless one has a nasty swamp with loads of organic material in it.

 

[Floater]

Thank you and agreed that in my particular situation was "painless" I didn't mean to sound like it always is for everyone. I did have quite a bit of organic material myself and pulled out as much as I could with my net (bending my pole in process); figured that the less work the chemicals had to do the quicker it would be. I just wanted to let people know that turning their swamp to beautiful sparkling water is possible as long as they hit it hard and don't hold back until they've achieved "the kill" and perfect water balance!