Anyone double SLAM before putting winter cover on or really no need?

[Ticojpunk]

In the past before I found TFP, I'd double "shock" the pool. Granted I wasn't really aware of my CYA levels so I never factored that in, but I do know I've opened up to crystal clear water.

I have my CYA at 40. When closing do I really only need to bring the chlorine to 16ppm and keep it there for 48 hours before closing. I can't help but be worried the chlorine will drop over nearly 8 months of closure. Last year I had a couple falling branches break through my winter cover, so when I opened the pool there was some debris in the water, not a lot, but it stayed clear, but there was a lot of chlorine in there. My CYA was sky high though, because AFTER refilling (had dropped water level below skimmer and return jet), my CYA at 110 or so.

Just trying to make sure I do the right thing now that I'm on to nothing but liquid chlorine and manual management of CYA.

 

[Bperry]

I have my CYA at 40. When closing do I really only need to bring the chlorine to 16ppm and keep it there for 48 hours before closing. I can't help but be worried the chlorine will drop over nearly 8 months of closure.

You don’t need to do that but many of us do. Going higher than that risks damage to equipment and pool surfaces. If you close after the water reaches <60F and open before 60F, the water down here stays pretty clear. Some folks with long winters use a good algaecide over the winter but higher chlorine will degrade that.

 

[Ticojpunk]

You don’t need to do that but many of us do. Going higher than that risks damage to equipment and pool surfaces. If you close after the water reaches <60F and open before 60F, the water down here stays pretty clear. Some folks with long winters use a good algaecide over the winter but higher chlorine will degrade that.

So the advice is that "little extra security" should probably be done by adding the algaecide rather than having over-chlorinated water break down your liner all winter?

If that's the case, how much Algaecide 60 should one put into a 10,000g pool for winter algae deterrent purposes?

 

[Bperry]

So the advice is that "little extra security" should probably be done by adding the algaecide rather than having over-chlorinated water break down your liner all winter?

TFP never advises going above SLAM level, even for closing.

If that's the case, how much Algaecide 60 should one put into a 10,000g pool for winter algae deterrent purposes?

That I can’t help with, I’ve never needed to use that stuff. Most people seem to just raise to SLAM level, close it down and go enjoy the winter.

 

[SoDel]

I’ve never added anything special or upped FC prior to closing, literally one day it’s open, the next closed, and have never had any kind of algae issue. FC level has to drop to zero at some point over the winter because it’s always zero on opening. That has lead me to not worry about it until Spring (plus Fall is a busy time here so the can gets kicked). On opening, the water remains clear, no algae. My sense of it is, winter algae prevention has more to do with cold water temps than trying to keep FC in a closed pool.

 

[Newdude]

My sense of it is, winter algae prevention has more to do with cold water temps than trying to keep FC in a closed pool.

The FC is insurance when it warms up for a few weeks during the off season. I got bit once and I should have seen it coming when we were laughing about wearing shorts in the 70s in February. It was all fun and games with several warm spells until I popped the cover in April.

For those of us who need to drain periodically, it only takes a few more minutes to use the submersible to mix and dose if the FC dipped.

 

[wireform]

I find by having the water lower in the pool and having a lager gap between the underside of the cover and the water, there's less chance eventhough you can have a few hot burning sun days in the winter.