Polyquat 60 to close - use up FC?

[Doug Reed]

Hi. First time closing my 22k IG with mesh cover

My question - my FC went from 6.2 ppm day before closing to 1.2 ppm 6 days after closing. Sounds like a-lot. Did the Polyquat 60 do that?

Here are some more details:
Water temp 58 at closing,, 55 today
today FC = 1.2 ppm, CC = 0.4 ppm, ph = 7.4
CYA = 40
Did not lower water level to close - right at top of overflow with recent rains (before closing)
Blew out both returns and inlet plumbing, obv pump off
Took today's water sample from skimmer box, as low as box is (maybe foot deep).
Use liquid chlorine and have had fantastic control all summer long, thanks to this forum. (kept FC at around 3-6 ppm all year at CYA = 40ish)

Last year had pros close and woke up this spring to fairly greenish water. Just trying to do a little better. Was planning to perhaps check FC over first part of fall and maybe add through cover if warranted. But didn't know if the Polyquat fouled up FC readings.

Advice?

Doug

 

[Saturn94]

It’s been my experience that adding polyquat does lower FC a bit. When closing (October), I add polyquat and let it circulate for a day. I then bring FC back up to SLAM level then close it up and cover (solid tarp over mesh safety cover).

I never have visible algae when I open in May.

 

[ajw22]

Algaecide - Further Reading

www.troublefreepool.com

​

How To Use Polyquat 60​

The following is Buckman Labs’ recommendation on how to use Polyquat 60 for closing your pool for the season.

As they recommend for proper winterization, the pool should be "shocked" with about 5-10ppm chlorine to destroy any lingering oxidant demand and remove any residual ammonia or chloramine, etc. After a couple of days, adjust the pH back to 7.2-7.6 and then add Polyquat 60 at the maximum rate as instructed per the label. This approach allows you to receive the highest benefit from both chemicals.

Note that Polyquat and linear quat algaecides are organic compounds that are known to cause interference's with certain color indicating reagents like pH indicators. Adjust the pH before adding Polyquat 60 and there is no reason to test pH after adding it.

Another point that they make regarding using this algaecide in pool water is that after the addition of Polyquat 60, it’s important to keep the circulation pump on for at least 24 hours to make sure that the algaecide is thoroughly distributed throughout the pool.

If you raise your water to SLAM FC level then you should let the FC drift down before adding Polyquat 60. Having a moderately higher level (½ SLAM level so the FC/CYA ratio of 20%) is okay as well. The idea is that the Polyquat should last through the winter even if the chlorine does not.[11]

Buckman Labs says that even if the Polyquat is broken down, it is still effective when used as an algaecide. Moderate to high levels of chlorine break down Polyquat but it still only transforms the formula into shorter chain polymers that are still just as effective

 

[thefloatqueen]

Yes, your FC dropped because of the Polyquat 60. I used it one year and wouldn’t do it again.
Polyquat isn’t necessary at all if all chemicals are balanced, pool is clean, water temperatures consistently below 60 degrees Fahrenheit, and FC is at SLAM-level before throwing the cover on. PQ60 eats up a lot of FC which sounds counterproductive to me — especially considering you’re instructed to close at half-SLAM if using it instead of full SLAM without it (make it make sense?! ). Closing late (even when no one can swim) and opening as early as possible are the biggest keys to opening up to crystal clear water in the spring! I try to shoot for late March (if water isn’t frozen) to early April. Never had a speck of algae.

 

[Saturn94]

…water temperatures consistently below 60 degrees Fahrenheit…

This is where we sometimes run into issues in this area (SE coastal Va). The water doesn’t stay consistently below 60° all winter. The first few years of pool ownership (mesh cover, no tarp) I would sometimes open to a green pool even when closing in late Nov/early Dec and opening in early March.

This is basically what I do;

Bring FC up to SLAM.
Wait a few days for FC to drop a bit.
Add polyquat and let circulate a day.
Bring FC back up to SLAM and close/cover it up.

I close in October and open in early May. Sometimes there is still some FC at opening, sometimes not. I cover the mesh safety cover with a solid tarp (this makes a big difference in my experience). Never any algae at opening.

I must admit I’ve not tried forgoing adding polyquat at closing since what I do has resulted in an easy opening year after year (been doing this many years).

 

[Doug Reed]

Awesome replies - very informative. Thanks. I added the polyquat and thought it’s a few bucks, why not. I suppose next year I’ll do without. Only my second year but I suspect I won’t see 60 degrees until it warms back up in 6 months.

Today I added 2.5 gallons of 12.5% around the perimeter, through the mesh cover, a few feet in from the edge. I suspect it will mix pretty well. Or at least I hope it does! I’ll check levels tomorrow.

I closed last week because if I do it later I thought my arms might freeze off from trying to plug the inlets with all the bubbling water coming up and reaching down to screw the things in. As it was they were a Bit numb!

Saturn - the tarp - does it belly and collect water? Interesting idea. I assume you do it to keep dirt and junk out? You tie down using mesh -perimeter bolts? To keep from bellying maybe put an exercise ball over mesh but under tarp?

 

[Saturn94]

Saturn - the tarp - does it belly and collect water? Interesting idea. I assume you do it to keep dirt and junk out? You tie down using mesh -perimeter bolts? To keep from bellying maybe put an exercise ball over mesh but under tarp?

The solid tarp does collect water, so it must be pumped off periodically. I never thought about putting anything between the tarp and mesh cover to prevent water from collecting on top. I wonder how such a setup would hold up in high winds?

Yes, my initial motivation for adding the solid tarp was to keep fine dirt/debris out to make spring opening/cleaning easier. The mesh cover would let fine dirt through, so at opening I had to vacuum the pool multiple times. Adding the tarp makes spring cleanup MUCH easier! The tarp also blocks out light which seems to prevent algae growth. One year I wasn’t able to open until June, and despite the water temp being 80°, to my surprise there was no visible algae!

To secure the tarp, I tuck the edges under the mesh cover and use bleach bottles filled with water to hold it down.

 

[thefloatqueen]

The solid tarp does collect water, so it must be pumped off periodically. I never thought about putting anything between the tarp and mesh cover to prevent water from collecting on top. I wonder how such a setup would hold up in high winds?

Yes, my initial motivation for adding the solid tarp was to keep fine dirt/debris out to make spring opening/cleaning easier. The mesh cover would let fine dirt through, so at opening I had to vacuum the pool multiple times. Adding the tarp makes spring cleanup MUCH easier! The tarp also blocks out light which seems to prevent algae growth. One year I wasn’t able to open until June, and despite the water temp being 80°, to my surprise there was no visible algae!

To secure the tarp, I tuck the edges under the mesh cover and use bleach bottles filled with water to hold it down.
View attachment 457937

Oh my! My dogs would knock those over every day just to annoy me.

 

[RickRude]

I too experienced a larger-than-normal loss in FC after adding PQ60. I had bought a few quarts months ago before I found TFP, and still had 1 quart on hand. For 2 months I consistently lost <= 2 ppm of FC per day. Then two nights before a 10 day business trip, I decided to throw in that last quart of ployquat to give my wife a little boost as she took care of the pool herself in my absence. 24 hours later I'd dropped 4 ppm of FC. She didn't need the extra boost anyways, so I'll never need to buy polyquat again.

 

[Doug Reed]

The solid tarp does collect water, so it must be pumped off periodically. I never thought about putting anything between the tarp and mesh cover to prevent water from collecting on top. I wonder how such a setup would hold up in high winds?

Yes, my initial motivation for adding the solid tarp was to keep fine dirt/debris out to make spring opening/cleaning easier. The mesh cover would let fine dirt through, so at opening I had to vacuum the pool multiple times. Adding the tarp makes spring cleanup MUCH easier! The tarp also blocks out light which seems to prevent algae growth. One year I wasn’t able to open until June, and despite the water temp being 80°, to my surprise there was no visible algae!

To secure the tarp, I tuck the edges under the mesh cover and use bleach bottles filled with water to hold it down.
View attachment 457937

Saturn, I added a solid cover over my LoopLok, like you. We had our first rain, and now its bellyed with water. Does it matter? The loopLok is holding it up. They show it holding up an elephant! Does it matter that it is bellyed with water? You said you pumped yours off?

Doug

 

[Saturn94]

Saturn, I added a solid cover over my LoopLok, like you. We had our first rain, and now its bellyed with water. Does it matter? The loopLok is holding it up. They show it holding up an elephant! Does it matter that it is bellyed with water? You said you pumped yours off?

Doug

I would pump the excess water off for safety reasons and to reduce stress on your safety cover.

 

[Casey]

Today I added 2.5 gallons of 12.5% around the perimeter, through the mesh cover, a few feet in from the edge. I suspect it will mix pretty well. Or at least I hope it does! I’ll check levels tomorrow.

You're not adding chlorine onto the top of the cover are you? The way I read that was you poured the chlorine on top of the cover so it can seap through. I hope I read that wrong. You will ruin the cover exposing it to chlorine like that.

As far as opening green while using a mesh cover.... you're never going to open to a crystal clear pool because the mesh allows sunlight, water and fine debris through the cover. If you don't want that, then go ahead and cover with another tarp but you'll have to keep the standing water off it.

Once the pool is winterized, it should be done accepting chemicals unless you peel the cover back and brush it through so its not settled in one area to discolor the finish (vinyl, fiberglass or plaster). I'm not about all that work once i close. I'll slam the pool in the spring when I open it.

 

[Doug Reed]

Actually yes, I did pour 12.5% directly through the cover, then chased it with plain water. I first was advised to do it by my local pool store (pour some in in early spring), then I called Loop Lok and they told me OK to do it. I think the water rinse will have negated any bad consequences. I did add a solid tarp and am pumping water off after rains.