Old Chlorine

[pb4uswim]

At the beginning of the season (around May) I bought 2 cases of chlorine and only used 1 so I have four gallons left from then to use to close my pool. Question I have is, does chlorine degrade over that amount of time? If so, does it just get weak, or does something else happen? If it just gets weak, I’m assuming that if I get the reading I want (say 15ppm), even if it takes all four gallons (which it shouldn’t if they were fresh), I would be good to go. But if it degrades in other ways, maybe I shouldn’t use it for closing (since I’m relying on it for months to keep the pool clean).

Basically - Use old chlorine to close? Yes or no?

Thanks.

 

[koffey]

Yes chlorine degrades in strength and the only by product of it is water so it self dilutes. Don't let it freeze.

 

[Newdude]

+1. It only degrades due to not being stable at 12.5% (etc). As it loses strength it becomes more stable. Once it's mixed in the pool it won't degrade faster as several old gallons achieving your target, or one strong jug to do the same.

10ppm is SUPER diluted compared to 10%

 

[pb4uswim]

Thanks. I’ll dump them and Get more if needed. I probably won’t as I’m going to put the safety cover on while the water cools down and leave the pump running for a few weeks with the SWG on. That will bring the chlorine up enough that the liquid may not even be needed, but I’ll throw some in anyway. I’m also thinking about using Polyquat this year as last opening, I did have some algae. Of course nothing serious and nothing a few gallons of chlorine didn’t handle. Still, I didn’t like seeing it.

 

[Newdude]

I’m also thinking about using Polyquat this year as last opening, I did have some algae

Polyquat is only for when you have 0 FC. Otherwise they fight and you end up with less of each, which is why out PQ closing rec is half SLAM + PQ, or full SLAM with no PQ.

Ideally you peek under the cover just beside it freezes and raise it back to SLAM (cheaper), or add PQ then. Either will bridge you for the tundra part of the season and check again once it thaws.

 

[Casey]

Use the chlorine. I'm still using 10% chlorine that has degraded and went through a house fire 2 years ago. It suffered water damage. Other than it losing its potency, it has been chlorinating my hot tub and brought me through 10 days of the pool being down while I fixed it. It's fine. Use it up. You may need more to hit your target but it's not going to hurt n you're not wasting it.