SLAM before closing -

[BlueEye14]

Sorry if I'm duplicating discussion, but this felt just slightly different from some of the other posts I've read with a similar question.
Anticipating my second pool closing soon -
The pool is not heated and has typically been uncomfortably cold enough to swim in at all in the days or week after Labor Day. Last year I kept the pool open a month after the last swim hoping to hit the magic 'cool enough' temperatures when closing, to open a cleaner pool. SLAMmed the pool before closing, but this didn't have much effect. Opened a green pool in spring.
It just is not cost-effective to keep the pool open long enough or open it early enough to entirely avoid opening to algae. Beyond that, the time and effort to maintain the pool for months before and after we can actually use it doesn't feel worth it. It's a small pool, ~8000gallons and has been fairly simple to clear up when required.
My question is whether, given the conditions I anticipate in the time after closing or before opening, it remains worthwhile to bother with a SLAM before closing when I have no reason to believe this will prevent opening to a green pool?
Am I missing or overlooking something? Any thoughts would be appreciated.

 

[ajw22]

Do you have a mesh or solid cover?

Have you tried using Polyquat 60 before closing?

Algaecide - Further Reading

www.troublefreepool.com

 

[BlueEye14]

loop-loc mesh cover
Have not tried polyquat 60 before - but the algaecide post suggests it as most effective when closing late and opening early. If I'm closing early/opening late when water is warm (above 60), doesn't it follow that'll it'll degrade like chlorine would (even if it does so a bit more slowly)?

 

[ajw22]

loop-loc mesh cover
Have not tried polyquat 60 before - but the algaecide post suggests it as most effective when closing late and opening early. If I'm closing early/opening late when water is warm (above 60), doesn't it follow that'll it'll degrade like chlorine would (even if it does so a bit more slowly)?

Wear a belt and suspenders.

Get your water as algae free as possible with chlorine and then add Polyqust 60. Between them they will give you the best chance of a clean opening.

There are no guarantees of a clean opening when you have a mesh cover.

 

[Newdude]

When are you opening ? There's 2 parts to the equation. Once covered, you don't know at opening if it's been green for a month, or 5 months.

Many have had the same concerns of the maintenance and cost needed to remain open late and open early, but our UV demand is already dropping like a brick and it will be very low soon. After that, the daily dose might last a week or more. The same goes with opening early. You need next to no chlorine dosing at first. 2 week stretches whittle down to weekly then twice a week and eventually daily.

So yes you still need to maintain the FC, but no, it's not nearly what it is in June, July and August.

A little bit of effort in the cooler months pays spades when you don't need a ton of work opening with a swamp.

 

[Newdude]

Oooooooh. I can give you a local reference for UV loss too.

My 60% in season SWG generation time (of 24 hours) is already down to 40%. Very soon it will be 20% and two weeks later it'll be 10%. For October, I'll fiddle with it in the single digit %s because some days the pool will lose just a little FC, and others nothing measurable. Whatever that equates to your production #s, you will see similar.

I close when the cell shuts off around the first week in Nov. You don't need to go that long, we just have the pool obnoxiously front and center with lots of visibility from inside and want to look at it as long as possible.

 

[sande005]

After many decades - I've found that doing a treatment just before closing doesn't have much effect. PolyQuat does help some. But you are at the mercy of the weather as to how long any extra Cl lasts to remain effective. So later is better than early, but there is always a weather gamble. The critical is to uncover as early as possible. Since mine freezes solid over the winter, that would be mid-April. I even have a giant ice cube still in the pool when peeling the cover off. Even if it is too risky from freezing to start up the pump, a gallon or two of Cl at that point helps a lot. Repeat as needed until pipe freezing danger is over. I do bring the water sample in to warm, before testing. At that point, my only concern is the Cl level. When very cold (<40 !) added Cl lasts a pretty long time. There may be dirt and worms in the bottom (mesh cover), but little/no algae. If I wait to uncover even a couple of weeks later, then I am busy getting the green out of the pool, and into the lawn. Not fun. It is very pretty to see snow falling on an open pool!

 

[BlueEye14]

I appreciate the responses and the local reference!
I also appreciate the SWG generation time point - I've still been fiddling with this as I learn the pool and process.
Year one, I opened late July, but that was a fluke because we needed to put a fence around the pool before I was comfortable opening after moving into the house (as well as the learning curve of trying to do some of this myself).
This past year I opened early June (it was green, but definitely more clear than last year - I figured either because I closed mid-October, or because of the way I shocked the pool right before closing).
In the future I think I'm going to try and do mid-to-late May. Before then runs me into the same issues I had closing in October last year.
I understand the rationale for doing this (on both sides of winter) when it's colder, it just doesn't feel worth the effort. Given the size of the pool, it hasn't been particularly difficult getting it clear (although I only have a small sample size). My primary question which I think you've been answering is whether it's of any true benefit and worth the cost of throwing a bunch of shock in before closing. It sounds like the answer is yes. Even if it keeps a FC level in the pool a bit longer, delays the algae growth - the degree of mess in the pool may well be less when I open?

 

[Newdude]

Even if it keeps a FC level in the pool a bit longer, delays the algae growth - the degree of mess in the pool may well be less when I open?

Yup. The mission is to still have some FC left when the water gets cold, then get it going again before the water warms up. If it's on the fence, one warm whoopsie week in the fall is all it takes to start the green. The longer it festers, the worse it gets so delaying that bloom as late as possible is preferable if you're going to lose the battle.

In the spring, green or not, you want to open as early as possible so either you stay clear, or the algae isn't growing exponentially yet. Cool water slams are way easier than June slams.

 

[sande005]

Well, you're taking a big chance with late May.....some years you may be fine, others you will be in pea soup heaven. Uncovering is uncovering - same work no matter when. With the water cold/very cold (and low seasonal sunlight), Cl lasts a long time. So time and cost will be minimal. No need to fire up everything until later. But a few gallons of Cl is worth the effort in prevention.