Winterising Pool Australia

Scollops

Active member
Jan 22, 2021
42
Brisbane
Pool Size
40000
Surface
Plaster
Chlorine
Salt Water Generator
Hi just wanted some knowledge of how to prepare a pool for winter. Assuming will be pretty much the same as is, maybe reduction in FC ? Appreciate in Brissy we have until maybe May but thought I’d ask whilst learning the ropes.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
36,444
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Does it freeze in Brisbane?
 

Scollops

Active member
Jan 22, 2021
42
Brisbane
Pool Size
40000
Surface
Plaster
Chlorine
Salt Water Generator
interesting Reverse of what I was told before I seen the light.
 

mgtfp

Bronze Supporter
Mar 5, 2020
821
Melbourne, Australia
Pool Size
66000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Astral VX 7T
You can let the CYA come down a bit, and get back to to the 70-80 range in spring. But keep the FC as you would in summer for the CYA you're at. Yes algae get's less active in colder water and doesn't grow as fast, but that also means slower metabolism and it's actually harder for chlorine to get into cells and kill them. And with lower temperature, CYA will bind more chlorine, reducing the amount of active chlorine. By leaving FC at normal levels, you compensate for these effects.

You will need a lot less chlorine per day. You will notice that at some point, when UV gets less intense, probably also more shade on the pool with the sun being lower, that your FC will start to shoot up - time to dial back the SWG, and reduce the pump time a bit. Since you won't have high UV losses, there is no harm in having the FC a bit higher at times (no harm in the sense that it doesn't cost you much in SWG run time). Once you get to a stable situation, it should be enough to test FC and pH about once or twice per week (another reason to keep the FC at summer targets, or even slightly higher - it gives you some buffer while paying less attention to your pool). Test TA, CH and CYA from time to time, depending on the amount of rain dilution they can slowly drift down over winter and affect your CSI (colder water will also reduce CSI, which is why allowing higher pH is a good idea - pH will naturally get higher with lower temperatures).

Don't miss the time in spring when you have to ramp up the chlorine production again - once the water gets warmer, algae will use any weakness in your chlorine levels to let you know that they are there.
 

AUSpool

Gold Supporter
Bronze Supporter
LifeTime Supporter
TFP Guide
Sep 23, 2015
913
Brisbane, Australia.
Pool Size
5000
Surface
Plaster
Chlorine
Salt Water Generator
In winter Aussie pools become water features. Just adding to what’s been said but going back to the opening question your don’t reduce the FC. The FC and CYA/FC ration remain the same but we need less bleach or SWCG run time to maintain our FC.

One thing to keep an eye on with a plaster or pebblecrete pool is you CSI. As it gets cold you CSI will decrease. Letting your pH creep up will help increase your CSI. But you may find your pH wants to setttle at 7.8 and managing it any higher becomes troublesome. From this point I let my TA creep up over winter and that helps my CSI stay closer to zero.

Letting TA creep up is easy since its in our tap water. Come spring a couple of acid doses will bring it back down again.

Keep an eye on you SWCG as the water gets to its coldest. I have never had a SWCG shut down due to cold water but I notice it is a feature of my new chlorinator.

Scollops, it will held if you update your signature a little. An above ground pool is generally thought of as a vinyl lined pool. I would call yours an above ground concrete plaster or pebblecrete pool. And add your filter type, Baker make a Hydro cartridge and sand filter.
 

mgtfp

Bronze Supporter
Mar 5, 2020
821
Melbourne, Australia
Pool Size
66000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Astral VX 7T
I have never had a SWCG shut down due to cold water but I notice it is a feature of my new chlorinator.

Good to know. My 2005 (cell seems to have been replaced in 2007) Hurlcon (now AstralPool Australia) just keeps producing all year. Never had a cold water reduction or even shut down, thought that was a "feature" of Aussie models (once the water is below about 21°C, the low salt light comes on, but I learned to ignore that - that's why I got an electric salinity tester to have an easy way to keep an eye on salt). Obviously not with the newer models.

One half in me wants to upgrade to something newer, but the other half wants to see how long I can keep this dinosaur running.
 

Scollops

Active member
Jan 22, 2021
42
Brisbane
Pool Size
40000
Surface
Plaster
Chlorine
Salt Water Generator
Interesting I purposely set my SWG to 4ppm each day I started the week with 10 FC (added chlorine) - just measured today it’s only 3FC about a week. Pool is 28 degrees apparently - it’s rained a little an not many people in the pool this week. Thinking output isn’t hitting the Mark ?

is there an SWG Test for output. My OCLT tests ( I did two to be sure were both zero loss so no nasties, pool is crystal clear.

Would indicate close to 3FC or more loss per day - assuming humidity and temp here in Brisbane is likely ?

PH crept up to 7.8 in the week no other changes really.
 

AUSpool

Gold Supporter
Bronze Supporter
LifeTime Supporter
TFP Guide
Sep 23, 2015
913
Brisbane, Australia.
Pool Size
5000
Surface
Plaster
Chlorine
Salt Water Generator
To start, pools are a game of grenades rather than darts, in that super accuracy is not needed. Daily then weakly tweaking when you get the feel of it is what’s required.

Its a bit ambiguous but if you started at a FC of 10ppm and a week later your at 3ppm then you need to turn it up a little. I like to creep up on my target but maintain it with bleach while I’m doing it.

So if I’ve tested and dosed my CYA to 70ppm (I’m conservative) my target FC is 5ppm. I actually call 5ppm my minimum and target 6ppm. So if you’ve set you SWCG at 4ppm*, lets guess its at 5 hours @ 80%, and your FC is at 10ppm. A week later your FC is at 3ppm I would use the app or PoolMath to dose some bleach to manually bring your FC up to 6ppm and turn your SWCG up a little, say 5.5hours @ 80% or 5 hours @ 90%. Then test and repeat until you reach equilibrium.
No there is no SWCG output test but I guess you could do an overnight free chlorine increase test?

Has your pH gone beyond 7.8 or dose it appear stable there?

*Your SWCG is a bit fancy if you can set it at a ppm output, most have adjustable time and output functions.
 

Enjoying this content?

Support TFP with a donation.

Give Support

Scollops

Active member
Jan 22, 2021
42
Brisbane
Pool Size
40000
Surface
Plaster
Chlorine
Salt Water Generator
@AUSpool thanks PH has usually been in the 7.2-7.6 dropping in acid each week to balance as per shop. Seeing the light coming to TFP forum now watching and checking, I believe swg do increase PH so that’s ok I can deal with the small increase. Was more FC loss in a week , but hey like you say so many variables as long as I maintain the recommended.
 

AUSpool

Gold Supporter
Bronze Supporter
LifeTime Supporter
TFP Guide
Sep 23, 2015
913
Brisbane, Australia.
Pool Size
5000
Surface
Plaster
Chlorine
Salt Water Generator
If you feel the need to adjust pH don’t take it down to 7.2 unless your purposely trying to lower your TA. If you want a pH of 7.6 only dose enough acid to get to 7.6.

Ive tested/managed a bunch of SWCG, pebblecrete pools on the sunny coast that all wanted to stabilise with a pH of 7.8. And now my new pool in brissy is pausing at 7.8.

Keep an eye on it, but if your pool likes to settle at a pH of 7.8 let it do just that and manage your TA and CH to keep your CSI within range.
 
  • Like
Reactions: Scollops
Thread Status
Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.