First time doing my own closing: Poly60 brands?

JaySee

Well-known member
Jun 29, 2021
61
Toronto
Pool Size
70000
Surface
Vinyl
Chlorine
Liquid Chlorine
Hi All,
I'm prepping to do my own closing for the first time this year, and around these parts (Toronto, Ont.) there's not a lot to choose from.

Does anyone have experience with these readily available algaecides:

Omni Algaecide 60

or

HTH EXTRA 60% ALGAECIDE


Alternatively, the guys who closed my pool last year just dropped 20 litres of chlorine into the pool at the end and called it a day. Would that better than using "off brand" algaecides? I'll need to close the pool earlier this year because we'll be away, and the water temperature won't have dropped to the optimal below 65F, more like low 70ish.

Thanks!
 
Last edited:
Thanks!
A semi-related question: Since I'm closing before the 65F standard, would be more advisable to close on SLAM levels, and then add Poly60 *later* once the temperature drops. Like, lift the cover and pour in a bottle into the drained pool.
 
When I used algecide I'd add 1/4 bottle to a bucket of water and then dump that in the pool and it dispersed REALLY well.

Since then, I've learned that PQ and Chlorine fight it out and you end up with less of each. That's why we recommend half SLAM level for PQ users instead of full SLAM, so the chlorine doesnt consume most/all of your PQ.

Once covered a pool will keep SLAM FC very well, even if it's not quite ideal closing temps.
 
When I used algecide I'd add 1/4 bottle to a bucket of water and then dump that in the pool and it dispersed REALLY well.

Since then, I've learned that PQ and Chlorine fight it out and you end up with less of each. That's why we recommend half SLAM level for PQ users instead of full SLAM, so the chlorine doesnt consume most/all of your PQ.

Once covered a pool will keep SLAM FC very well, even if it's not quite ideal closing temps.

Fantastic. I think I'll close on SLAM and add diluted PQ later once the FC drops. I have a safety cover so most likely the FC will drop faster than a nonpermeable cover. Is there a downside to adding too much PQ into a half-drained pool?
 
. I have a safety cover so most likely the FC will drop faster than a nonpermeable cover.
I just ordered one myself, and it's 98% solid, so expect roughly that much UV blockage. It will do pretty darn well for 'not being solid'
Is there a downside to adding too much PQ into a half-drained pool?
I don't think so given a reasonable 'too much'. For example, 250 gallons of anything would be bad. :ROFLMAO:

Let's ask @JoyfulNoise for his science thoughts.
 
Too much of anything is never a good thing as I recently experienced with an old bottle of Baily’s Irish Crème … 🥴

However, as long as you’re not dumping 10 gallons of PQ60 in your pool, your real concern is how to disperse it once the pool is closed and the equipment can’t be run. If you can pull the whole cover, add your PQ dose and give it a good brush, then ok. However, if you dose it and leave it, it’s just going to pool at the bottom and slowly disperse. That’s not very effective.
 
However, if you dose it and leave it, it’s just going to pool at the bottom and slowly disperse. That’s not very effective.
Diluting it in a bucket first made a full pool cloud. I'm sure some of it had to settle, but it clouded up so well it made me sad to ruin the previously crystal water.
 
Hi All,
I'm prepping to do my own closing for the first time this year, and around these parts (Toronto, Ont.) there's not a lot to choose from.

Does anyone have experience with these readily available algaecides:

Omni Algaecide 60

or

HTH EXTRA 60% ALGAECIDE


Alternatively, the guys who closed my pool last year just dropped 20 litres of chlorine into the pool at the end and called it a day. Would that better than using "off brand" algaecides? I'll need to close the pool earlier this year because we'll be away, and the water temperature won't have dropped to the optimal below 65F, more like low 70ish.

Thanks!
I know that this is probably against all the TFP teaching but all I do every year for the past 35 or so years for closing is to throw in 3-4 gallons of bleach and close it up with the solid cover. When I open it up in the spring, it is clear and alge free. 18x33 above ground pool in Long Island NY.
 
I know that this is probably against all the TFP teaching but all I do every year for the past 35 or so years for closing is to throw in 3-4 gallons of bleach and close it up with the solid cover
With your 16k gallon pool, 4.5 gallons of 10% is SLAM level 28FC for the average SWG pool with a 70 CYA. So 3 gallons would put you a bit under SLAM, yet still plenty elevated to start the off season. (y)

The only thing anti TFP about the above is that you didn't know exactly what it did for you.
 

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FWIW, I have a mesh safety cover and don’t use anything other than chlorine. And when I open back up in the spring, water has always been clear and still showing a bit of FC level when I test.
 
I know that this is probably against all the TFP teaching but all I do every year for the past 35 or so years for closing is to throw in 3-4 gallons of bleach and close it up with the solid cover. When I open it up in the spring, it is clear and alge free. 18x33 above ground pool in Long Island NY.

That seems to be a standard practice here as well for hired companies that open/close pools -- at the end of the process throw in 20 litres of chlorine into the half-drained pool, stir it around a bit with a brush and then cover it up. When opening it up, they'll brush, vacuum, throw in another 20 litres of LC and tell you to run the pump for 2-3 days. That being said, the pool has always opened to varying shades of emerald green. But with the sudden temperature fluctuations between hot, warm-but-not-hot-enough, and cold we get nowadays in southern Ontario it's almost to be expected...?
 
Semi-related: What are ppl's general opinions of using slow-release "winter pills" such as this:


I haven't heard much chatter about these, but I do recall a story of one of my pool guy's clients who rigged up a DIY stabilizer slow release system under their winter cover that apparently worked.
 
Semi-related: What are ppl's general opinions of using slow-release "winter pills" such as this:


I haven't heard much chatter about these, but I do recall a story of one of my pool guy's clients who rigged up a DIY stabilizer slow release system under their winter cover that apparently worked.

Not worth it. Mostly nonsense chemicals that don't do you any good. Simply follow TFPs advice on closing and your pool will be fine. Most pool owners that follow TFP's winter closing open to either clear pools or have such minor issues that the pool is balanced and ready to go in a week upon opening.

The best way to look at the pool chemical industry is this - 99% of what they sell is either completely unnecessary or absolute snake-oil. Just ignore the marketing hype. These aren't chemists, they are salespeople and their only goal is to make money.
 
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That seems to be a standard practice here as well for hired companies that open/close pools -- at the end of the process throw in 20 litres of chlorine into the half-drained pool, stir it around a bit with a brush and then cover it up. When opening it up, they'll brush, vacuum, throw in another 20 litres of LC and tell you to run the pump for 2-3 days. That being said, the pool has always opened to varying shades of emerald green. But with the sudden temperature fluctuations between hot, warm-but-not-hot-enough, and cold we get nowadays in southern Ontario it's almost to be expected...?
Green is Probably expected if the process is just dumping in unknown amounts of stuff that may not be needed or may be too much. Seems much easier to just measure the right amount, add it, then open up to crystal clear pool.
 
The biggest factor is closing/opening temperatures. If a pool owner can wait until the water temperature is below 60F before closing and then open when the water temp is still below 60F, there is very little chance of getting a green pool. Most species of algae stop replicating, or their reproduction rates plummet, when the water temp is below 60F. But I do understand that for some areas, waiting until the water is below 60F could mean trying to close a pool when snow is starting to fall ... not fun.
 
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The biggest factor is closing/opening temperatures. If a pool owner can wait until the water temperature is below 60F before closing and then open when the water temp is still below 60F, there is very little chance of getting a green pool. Most species of algae stop replicating, or their reproduction rates plummet, when the water temp is below 60F. But I do understand that for some areas, waiting until the water is below 60F could mean trying to close a pool when snow is starting to fall ... not fun.
I close mine when it’s around 60 to 65 degrees in Atlanta
It may bump FC up to 10 but it will last 4 or 5 months and my water looks perfect.
 
The biggest factor is closing/opening temperatures. If a pool owner can wait until the water temperature is below 60F before closing and then open when the water temp is still below 60F, there is very little chance of getting a green pool. Most species of algae stop replicating, or their reproduction rates plummet, when the water temp is below 60F. But I do understand that for some areas, waiting until the water is below 60F could mean trying to close a pool when snow is starting to fall ... not fun.

Last year we closed around 65F (15C) and then 2 weeks later we had a sudden heat spell close to 80F (27C) air temperature. And then there was the sudden 3-foot snow dump in 24 hours in January that we hadn't experienced since the 90s. It can get pretty wild. The upside is that it keeps CYA nice and low at opening!
 
We get random heatwaves here throughout the closed season- for this reason I occasionally peel back the cover & grab a sample along with a temp reading. Adding some additional liquid chlorine is easy to do if necessary.
 
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