1st year closing with SWG

[P00LNerd]

I took a measurement a little after sunset last night, for OCLT, and got 7.0 ppm. I actually went the extra mile and used the 25 mL (±0.2 ppm) test, whereas I normally just use the 10 mL (±0.5 ppm) test. I did find using the light on the speedstir a little challenging, very hard on eyes adjusted to dark, and it just looks... weird.

Then I retested just after sunrise this morning, same ±0.2 ppm version of the test, and got 7.8 ppm! So, I repeated the test using my more usual ±0.5 ppm method, and confirmed it was still pink at 7.0, yielding a result at 7.5 ppm.

So, I think my test this morning was good, I must have made some error last night. SWG was turned off just before doing test last night, and stayed off overnight.

Since my FC is plenty high (3.0 - 9.0 recommended), I may just leave the SWG off all day and tonight, out of curiosity to see what I lose in 24 hours from this morning to tomorrow morning. But I will still re-check tonight, so we can also have a proper "OCLT".

The pool is covered, and the cover is waterproof dark blue. I string it up on a zip line for washing it each spring, and it doesn't let any light thru, it's totally dark under that thing.

 

[Newdude]

I did find using the light on the speedstir a little challenging, very hard on eyes adjusted to dark, and it just looks... weird.

Bring the sample inside.

But I will still re-check tonight, so we can also have a proper "OCLT".

 

[Mdragger88]

I love the speed stir light and actually turn off the lights on purpose so i can see that perfectly clear glowing end point of the fc test

 

[P00LNerd]

I love the speed stir light and actually turn off the lights on purpose so i can see that perfectly clear glowing end point of the fc test

I find it difficult to look at, my eyes just don't adjust so well to light anymore. But I think the bigger problem for me was consistency, daylight for one test and then the speedstir light for the next. Whichever you prefer, I think you need to just stick to the same conditions everytime.

Anyway, I have 24 hours of results now, showing only 0.2 ppm drop from yesterday morning to this morning. I did a test last night as well, bringing the sample indoors after dark and using a combination of room lighting plus speedstir light... but I think it was falsely low again. So, I'd ignore the night-time reading and just look at the two mornings, which are within 0.2 ppm over 24 hours.

So, I guess it's time to add the polyquat 60 and raise to half SLAM? I could probably close one day this week, and I'm not sure if timing on the half slam level is important, or if I should hold it that high for several days before shutting down. I also have probably two gallons of liquid chlorine left in the cupboard from spring, so it might be worth just using that to raise FC, rather than storing it over winter.

 

[Mdragger88]

I’d definitely use up what lc you have.
The way I interpret the closing instructions are:
Raise fc to slam level (to kill anything funky),
Do an oclt (to prove funky stuff is dead),
Let fc fall to 1/2 of slam and add polyquat then close
or
Just close at slam level.

I do the last one.
My fc stays adequate all winter with this method so I don’t need polyquat aka “insurance”.
but if you’re not raising fc to slam level I don’t think it matters when you add the polyquat.

Closing an In Ground Pool

Winterizing a pool is essential for keeping your in-ground pool protected during cold-weather months. This Pool Repair guide will show you how to do it.

www.troublefreepool.com

 

[P00LNerd]

Raise fc to slam level (to kill anything funky),
Do an oclt (to prove funky stuff is dead),
Let fc fall to 1/2 of slam and add polyquat then close

I followed this, without really second-guessing it. But my current drop of 0.2 ppm per day, we'll be singing Christmas carols before my FC drops to anywhere near half-SLAM. Totally my fault, not blaming Mdragger.

We are already seeing pretty consistent daily lows in the mid-30's, so I guess my best bet is to save this fresh bottle of Polyquat 60 for next year, and just close at full SLAM level?

Any concerns with shutting down the heater and other equipment with this much residual chlorine? I'll blow them out, but have no easy way of flushing. Presently at 22 ppm.

 

[PoolStored]

Polyquat or no, should be fine. Personally, I’d add it.

No issues with heater etc.

 

[Mdragger88]

I followed this, without really second-guessing it. But my current drop of 0.2 ppm per day, we'll be singing Christmas carols before my FC drops to anywhere near half-SLAM. Totally my fault, not blaming Mdragger.

We are already seeing pretty consistent daily lows in the mid-30's, so I guess my best bet is to save this fresh bottle of Polyquat 60 for next year, and just close at full SLAM level?

Any concerns with shutting down the heater and other equipment with this much residual chlorine? I'll blow them out, but have no easy way of flushing. Presently at 22 ppm.

The only issue with adding polyquat at higher fc levels is that the fc degrades it a little more & the fc may get lowered a little - this happens no matter the fc level its just more pronounced at the higher levels thus the recommendation to add it after fc falls.
Its fine either way you choose to go. With or without.
Like I said, I choose to forgo it simply because my fc never falls too low so no need for the “insurance” polyquat provides. Just simpler for me. 1 less thing like Forrest Gump says

 

[P00LNerd]

I guess I don't follow the logic that if PQ60 lowers FC, you should only do it when FC is already lower. If it knocks FC down by a greater amount when FC is high, seems like FC will just converge closer to the same value, either way.

We have been at 35F - 36F the last several mornings, so I do need to get this thing closed at some point soon. I'll check FC later today, it's been 3 days since any chlorine check or addition.

 

[PoolStored]

I guess I don't follow the logic that if PQ60 lowers FC, you should only do it when FC is already lower. If it knocks FC down by a greater amount when FC is high, seems like FC will just converge closer to the same value, either way.

There is a long history of progression on TFP WRT understanding the use of PQ for closing.

What we learned is that at high levels of FC, the polyquat breaks down. At moderate levels of FC (~20% of CYA), or 1/2 SLAM it is broken down, but still effective when used as an algaecide.

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.

polyquat question

The guy at the pool store said Algae Destroyer by (Nature's Way) was what we needed when we asked for polyquat algaecide. (I looked at "Pool School" thread Winterizing above ground pools.) Is this what I should use. It has poly (oxyethylene (dimethyliminio) ethylene(dimethyliminio) ethylene...

www.troublefreepool.com

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.

Algaecide - Further Reading

www.troublefreepool.com

 

[P00LNerd]

I cannot find a single recommendation for dosing amount of PQ60 at closing. It’s not on the bottle, and Google just says follow bottle. How many oz per gallon?

 

[PoolStored]

11 ounces per 10,000 gallons of pool water.

 

[P00LNerd]

Thanks! Done.

 

[P00LNerd]

Pool was closed on Saturday. We had 29F this morning, so it was time. Water was holding 60F in the several days prior to closing.

I decided to take all of the SWG components and plumbing and put it into a patio storage chest that's used for the pool cover in summer. It's dry and out of the weather, albeit not climate-controlled. All other plumbing was blown dry and plugged.

We're due for a cold winter, if not this year then next, as we've had a few warm winters in a row. It's not uncommon for us to have a week of below-0F nights and daytime highs near 10F, although our more normal winter weather is 20F above that.

 

[dereksanders]

Indeed, it can get and stay frigid there. I bring in my equipment from the central IL winters. There’s no rhyme or reason here; it goes from unseasonably warm to frigid cold within a week.