When To Close Pool For Season...

[Thinkly]

We moved into this home this summer which has an in-ground viking fiberglass pool and now are approaching the end of swimming season. Our pool guy says that it is best to leave water in the pool all year, even here in Kansas where it gets to 0 F, many winters.

He also says it is best to close as late as possible and open as early as possible. To me that sounds like a way to sell more chemicals, but is there science behind this? We have a cover for the pool that will be installed at closing.

[mickey4paws]

You should definitely leave water in your pool all year round. When we close our pool for the winter, we bring the water level down below the returns. It's up to you when you close. We close around mid September because we get a lot of leaves that fall in the pool and it becomes too much of a hassle. If you have a heater, you can extend your swimming season a bit. We also usually open the first week of June or so.

[ps558]

We moved into this home this summer which has an in-ground viking fiberglass pool and now are approaching the end of swimming season. Our pool guy says that it is best to leave water in the pool all year, even here in Kansas where it gets to 0 F, many winters.

He also says it is best to close as late as possible and open as early as possible. To me that sounds like a way to sell more chemicals, but is there science behind this? We have a cover for the pool that will be installed at closing.

The reason we tell people to close late and open early is mostly due to the older mesh cover which let alot of debris in and turn the pool green after the sun hits it if the wether is warm in spring or fall.

If you have a new tighter mesh cover of solid cover the pool has less of a chance to turn. You can close antytime you want it is up to you. You can even do a chemical retreat in Nov and March. If you can wait until the water temp drops below 65 that is ideal. At the temp it is hard to get a algae bloom, if you don't want to wait super shock the pool, circulate for 24 hours and close it up.

I don't know what closing materials you have , but they make a skimmer blowout tube, thats lets you keep the water level were it is at

[jkusmier]

You should never drain a fiberglass pool - the shell is comparatively light and hydrostatic/ground water pressure can cause it to float, wreaking havoc on the pool's plumbing and surrounding deck. Proper closing entails adjusting the chemistry (especially pH), shocking the pool, vacuuming/skimming, allowing a good algaecide (any form of polyquat) to circulate, then draining ~2" below the returns, blowing the water out of the plumbing and equipment w/ a compressor or shop vac, adding marine/RV (pink) antifreeze into the skimmer and return lines, capping the lines and skimmer (use a "gizmo" for the skimmer) and using a siphon (a garden hose works great) or an external pump to keep the water level below the returns when winter precipitation raises the water level near or above the returns. You'll find tons of threads on this forum and at troublefreepools about proper winterization, including detailed accounts about the sequence.

I personally prefer to close late and open early. The less time your pool is covered and pump is off, the less time algae has to bloom - period. Many owners who adhere religiously to the traditional Labor Day closing date find a green swamp when they open the following spring - because algae thrives in sunlight and temps above ~50F, and many owners live in places which experience a stretch of warm, sunny days after Labor Day. I live in the Saint Louis area, and aim for a mid-late October closing and a mid-April opening (these timelines will vary depending upon your location). Mind you, I'm not swimming in late September or October, but the pool still provides visual interest, my SWG (Pentair IntelliChlor) keeps producing chlorine until the water temp reaches ~55F, and I've found you can reduce pump run times by roughly a third.

By following this forum alone, or along with troublefreepools, you will find a wealth of knowledge on how to minimize chemical use (and the corresponding expense).

[mrfixit]

Being in Canada, I close many pools for customers anywhere from labor day to early Nov. The bulk of the closings are mid to late Oct. Some people do have problems with algae in the spring, but properly treating the pool at closing and keeping the light out of it as much as possible goes a long way to having a clear pool in spring. Sunlight and water temp above 60 deg are the 2 main factors for algae growth. I do close many pools early in the season, and have no algae problems in the spring, but it depends on how the water is treated before closing that makes the difference.

And yes keep water in the pool thru winter.

[mickey4paws]

So do you guys recommend using something like Polyquat 60? Or would it be better to just shock before closing and then shock upon opening in the spring?

[jkusmier]

I would recommend it. You should shock to 40% of your CYA/stabilizer level a few nights before closing day. This will allow the FC/chlorine level to drop to levels acceptable for use of polyquat. Add the polyquat the night before closing (or at least 4-6 hours before) and let the pump run all the while. This is important, polyquat is very thick/viscous and it will take some time for it to fully dilute and circulate (you can speed things up by adding/diluting the polyquat in several 5-gallon buckets of pool water).

[mickey4paws]

I would recommend it. You should shock to 40% of your CYA/stabilizer level a few nights before closing day. This will allow the FC/chlorine level to drop to levels acceptable for use of polyquat. Add the polyquat the night before closing (or at least 4-6 hours before) and let the pump run all the while. This is important, polyquat is very thick/viscous and it will take some time for it to fully dilute and circulate (you can speed things up by adding/diluting the polyquat in several 5-gallon buckets of pool water).

Thanks so much for the reply. I was at Leslie's Pool store today and saw some Algaecide 60 and the main ingredient (60%) was poly-something. Would that be the same as polyquat 60?

[chem geek]

Yes, it's the same thing. Just look for something that contains 60% Poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichloride].

[mickey4paws]

Yes, it's the same thing. Just look for something that contains 60% Poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichloride].

Thanks, Chemgeek! I was reading some more posts where some people said they used the algaecide when they close, and others say that they don't use it and just shock their pool like crazy when they open in the spring.

I like to add as little chemicals to my pool as possible, but if I'm going to get algae, I think I'd rather add the algaecide at closing instead of fighting algae in the spring.

As far as dosing, would it be a maintenance dose, or a dose for someone who has algae already?

[jkusmier]

I add an entire bottle of polyquat 60 into my 16,000 Gallon pool the night before closing.

[mickey4paws]

I would recommend it. You should shock to 40% of your CYA/stabilizer level a few nights before closing day. This will allow the FC/chlorine level to drop to levels acceptable for use of polyquat. Add the polyquat the night before closing (or at least 4-6 hours before) and let the pump run all the while. This is important, polyquat is very thick/viscous and it will take some time for it to fully dilute and circulate (you can speed things up by adding/diluting the polyquat in several 5-gallon buckets of pool water).

We're closing the pool on Monday. I did want to be able to swim Saturday & Sunday if possible. Is it okay to add the shock Saturday morning and still swim later Saturday afternoon and Sunday? I also plan on adding the Polyquat Sunday evening around 6 pm and then let the filter run all night.

Does this sound okay?

[jkusmier]

Generally, you want to avoid swimming while the pool is at shock level, but I've swam in mine a few times after shocking earlier in the day. Worst result, realistically, is that it might fade your swimwear a tiny bit. That said, I'd recommend shocking Fri night (after you're done swimming if you swim Fri) if at all possible. Let the pump run overnight for circulation. Chlorine levels should be well below shock level by Sat afternoon.

[mickey4paws]

Thanks very much for the reply. Is there any reason I can't shock Sunday night and also add the Polyquat 60 at that time? We're closing Monday. Or, do I need more time for circulation?

Previously we had Baquacil so this is the first time closing it with chlorine. I have 9% liquid chlorine and according to the calculator, I'll need to shock to 24 FC. I also bought a quart of Polyquat 60.

So this weekend we want to be able to swim, but I'm not sure when we should shock and when we should add the Polyquat.

Can we add them at the same time, or is that not a good idea? When should we add the shock and when should we add the Polyquat?