Getting your pool ready for summer
What to do in early spring so you are not fixing a green pool in December. Five jobs, in the order they are worth doing.
Every year we get the same run of calls in late November. The water has gone cloudy, or green, and people want it swimmable by the weekend.
Almost all of those pools were fine in September. The problem is that nothing was done while it was still cool, and a pool that has been left alone over winter does not come back in an afternoon.
Here is the order we would do it in.
1. Start in spring, not in December
A pool that has sat through winter has low chlorine, unbalanced water and a filter full of last autumn's leaves. On its own that is not dramatic. Add warm water and sun and it moves quickly.
Algae likes warmth. Once the water comes up in temperature, a pool that was merely dull in August can turn in a matter of days.
Doing this in September buys you time to fix things slowly and cheaply. Doing it in December means doing it fast and expensively, usually with the pool out of action for the week you wanted to use it.
2. Get the water tested properly, not with a strip
A test strip tells you chlorine and pH. That is not enough to know what is going on.
The things that decide whether a pool behaves are underneath that: total alkalinity, calcium hardness, and stabiliser. Stabiliser is the one that quietly causes the most trouble, because it builds up over years and never leaves on its own.
If the stabiliser has climbed too high, chlorine stops working properly no matter how much you add. We have written about why chlorine stops holding separately, because it is the single most common reason a pool with plenty of chlorine in it still goes green.
The fix for that one is diluting the water, not adding more chemicals. Worth knowing before you spend a hundred dollars at the pool shop.
3. Check the gate before the kids are in the yard
This is the job nobody puts on the list, and it is the one that matters most.
Home pools are the most common place for toddlers to drown in Australia. When researchers look at how a child got in, the same causes keep coming up: a gate that had fallen into disrepair, or one that had been propped open.
Open your pool gate about halfway and let it go. It should swing shut and latch by itself, every time, without help. If it does not, that is a job for this week.
Then look at what is sitting near the fence. A pot plant, a bench, a delivery box — anything a child could climb changes what the fence does. The rules and the usual failure points are in our guide to NSW pool fence rules.
4. Work out what the pump is about to cost you
Summer is when the pump runs longest, so it is also when an inefficient one costs the most.
Pumps sold in Australia have had to carry an energy rating label since 1 October 2022. If yours predates that, nothing ever required it to be efficient, and the difference between ratings is large — published figures put a six-star pump at well under half the yearly power of a one-star.
Before you turn the hours up for summer, it is worth knowing which one you have. We have set out the numbers in what a pool pump costs to run.
5. If it has already gone green, stop and think
The instinct is to tip in a bucket of chlorine. On a properly green pool that usually wastes both the chlorine and the weekend.
Chlorine only works if the water underneath it is right. If the pH has drifted or the stabiliser is high, you can empty a drum into the pool and watch nothing happen.
The order that works is: balance the water first, then shock it, then filter hard and vacuum out what dies. Most pools are swimmable again within a few days that way.
If you would rather not spend the week on it, that is green pool recovery.
Where this came from
- Royal Life Saving Society Australia — National Drowning Reports
- Australian Government — Energy Rating — New mandatory standards and labelling requirements for swimming pool pumps