First IGP closing without a cover and have Algae - help please

[miles267]

Hi TFP forum users - as a result of last winter being unpredictable and hazardous, we opted to trying closing our pool this winter for the first time ever. We don’t have a cover and weren’t planning to get one in future if it can be avoided. (Not sure we’ll winterize again)

Had pool professionally closed in Sept. Now our plaster pool, without circulation, is turning green quickly due to mild weather and direct sunlight. No leaves in pool.

In an effort to avoid plaster staining or other issues. How do others manage this? Should I be using liquid chlorine and any particular algicide? I’m fine with balancing chems during season but this is my first winter without pump running. Not sure what to do? Please advise. Thanks.

 

[Texas Splash]

"Professionally closed" is a term that always scares me. If the techs didn't use a Poly 60 and/or you didn't do a pre-SLAM prior to closing, there's not much you can do now. As you stated, the unseasonably warm weather didn't help. To kill and remove algae you must run a SLAM Process through its entirety until you pass all 3 SLAM criteria. You can't do a SLAM unless the pump and filter are operational.

If you elect to leave the system closed, then all you can do is add some liquid chlorine and mix it well manually to help "try" and keep things from getting worse. When the colder water temps finally arrive, it should slow down algae growth and perhaps allow your chlorine to do a better job. As soon as you can in the spring, open up the pool and run a SLAM Process.

 

[miles267]

Thanks for your response. Sorry should’ve been more specific. As we don’t have a pool cover (and no leaves, nearby trees), at end of October, the pool company shut down the pump and filter, cleared the plumbing lines and installed inlet plugs, Gizmos in skimmers, and something listed as Pool Magic chemical/cleaner. We did not shock/SLAM before closing. I’ve continued to let the robot cleaner run several times a week as scheduled. Am using the Polaris ultra fine mesh filter basket in the robot. This evening, I added 2x 128 oz bottles of 10% liquid chlorine that I had leftover from end of season. Proceeded to brush the walls and agitate the water before activating the pool robot again. The water temperature is 51F.

 

[Newdude]

Whats done is done miles. Next year test/add/mix with the brush as often as needed. At 50 degrees thats probably a week or two. At some point the chlorine will last closer to a month. If you get a warm spell, test just to be sure you are well above minimum.

 

[wireform]

You can also drop in a submersible pump and let it run a while and move it to another spot and run it there to mix the water.

 

[miles267]

Woke up and checked pool today and all green is gone. It’s a bit cloudy but 256 oz of 10% liquid chlorine made a big impact. Checked water and it’s 52F and 3 ppm FC.

 

[Newdude]

It’s a lot easier to kill when it’s not growing exponentially, for sure. Hopefully you got most of it and if any remains it will be dormant soon. Usually now (being cloudy) we shift the focus of the fight to filtering out all the dead algae. With that not an option, run the robot a bunch with the fine filters. It will probably get most of what falls to the floor.

I’d keep the FC elevated for the foreseeable future. The sun won’t be burning it off much and you won’t lose any ground of anything is still alive. Keep occasional tabs on it as needed to make sure you have some FC left.

 

[miles267]

@Newdude when you say elevated FC, how high would you suggest? I’m currently at around 5 ppm FC. Thanks.

 

[Texas Splash]

when you say elevated FC, how high would you suggest?

That's where proper home testing would be valuable. But if you knew your CYA was a minimum of 30 for example, you can easily take your FC level up to 10 - 12 for now. If your CYA was higher, you could increase the FC even high. See the FC/CYA Levels to confirm (SLAM tab). You can't due a true SLAM Process at the moment, but that gives you an idea how the FC is balanced to the CYA. So you have plenty of wiggle room. The cold water is your friend right now, so I'd increase the FC to about 10, mix it around either manually or with a submersible pump, brush, and let the cold water and chlorine continue to to do its work for you.

 

[Newdude]

^^^^^^. Exactly what I was thinking. Not nearly Slam level but maybe 2X of normal target.

 

[miles267]

Tested pool water. 53F, FC 10, CC 0, CYA 70. But pH (>8.2). Running robot cleaner and submersible pump to keep water mixed. Added muriatic acid to bring pH down to 7.8 territory. Water a bit cloudy in the deep but pool otherwise spotless. Bring on the colder water temps now

 

[miles267]

Pool chemistry balanced despite pump off for winter. Water level lowered below tile line to safeguard against freezing. Upon doing so I noticed the lower water level doesn’t cover the surface of small entry step on our tanning shelf. The quartz/plaster finish seems to be every slightly flaking away in a few areas on this dry surface. What causes this? Must it be kept underwater during winter, regardless? Is it just usual wear and tear of pool surface? Thanks.