Swimming pools in the winter

[5MUG]

To all you folk who have swimming pools............do they stay full through the winter? If so, does a layer of ice form on them. Just curious as to maintenance through the cold months.

[caziques]

An inground pool should be left full of water, otherwise there is possibility of it being forced out of the ground.

Best to have a cover to stop sunlight(!) destroying chlorine and making it go green.

A saltwater pool will freeze at lower than 0c, freshwater pools will freeze at zero.

[Night Runner]

The grandparents had a large 'proper' indoor pool, they just didn't heat it during the winter.

It never froze, nor did catastrophe happen.

[m4ckg]

my parents have got an outdoor pool, they take the insulated cover off, they also leave some empty 5 litre containers floating in the water ( something to do with ice and exspansion? ) and the cover with a winter type to prevent leaves and debris getting into the pool

[Matt Harper]

There is a lot more to 'winterising' an outdoor pool than has been stated so far.
In a climate where sub-zero winter temps are possible, you need to drain down the water level to below the skimmer intake and close and purge the main drain and pool suction valves, before draining down the pump, filter and any heating system. You then need to 'hard-shock' with liquid chlorine, add stabilizer, algicide and hardner/acid, depending on your pools pH balance.
Finally cover to keep out winter debris and wildlife.
Just throwing a cover over it can lead to some horribly destructive water chemistry imbalances (calciate growth, most commonly) and frozen (i.e. buggered) plumbing, pump casing, filter media et. etc.

[spikeyhead]

m4ckg said:

my parents have got an outdoor pool, they take the insulated cover off, they also leave some empty 5 litre containers floating in the water ( something to do with ice and exspansion? ) and the cover with a winter type to prevent leaves and debris getting into the pool

When ice forms it expands and puts pressure on the poolside. It's far easier to cope with some squashed plastic bottles than it is the concrete side of a pool.

[minicab]

Another method is to fit your filtration system with a frost stat. This negates the need to drain the pool down - you will have to periodically empty some water out of the pool though as it fills up with rainwater etc.

The frost stat will fire up the filtration system when the temps get low, and ensure water keeps circulating so it doesn't freeze. This is actually preferable for the life of your pump, it will prefer being run periodically than left dormant for 7 months.

Use a long life alagecide to keep the water clean.

If you need any further advice, I can reccomend talking to these chaps: www.poolsuppliesltd.com