How to Winterise a Swimming Pool

Posted by Josh Abbott on

Winterising a Swimming Pool

For home pool owners it is natural lose interest in the pool once the swimming season is over.

For some (not all), this extends to being totally neglectful - with the thought to clean it up after winter, with a bomb load of chemicals, excessive vacuuming and elbow grease. This invariably results in a bigger expense than winter maintenance and the potential to get some staining which may need professional help to remove.

The most sensible approach is to make sure that, on pool closure, the pool is algae free & chemically well balanced and the sand (or glass) filter is backwashed. In the case of cartridge filters, they should be cleaned by soaking in an appropriate solution. In broad terms, good chemical balance is to ensure pH is 7.2-7.6, Total Alkalinity is 90-120mg/L and Chlorine is 1.0-3.0mg/L.

For those with a winter cover, that’s all you need to do. As these covers cut out all light, algae can’t grow. It is advisable, though, to turn the pump on for a few minutes each month to ensure equipment remains in good working order.

For those with a solar blanket - or no cover whatsoever - around 2 hours per day circulation is recommended together with diligence in maintaining good chemical balance & vacuuming all waste products regularly. Filters will still need the occasional backwash & clean - be guided by your pressure gauge.

Even with the procedures above, algae can contaminate the pool at any time. Small hand doses of chlorine or chlorination from a salt water generator (or other continuous disinfection system) will battle to kill algae once it has a foothold.

The recommended approach to minimise this situation is to Winterise with a QUALITY algaecide at close down and repeat doses every month. Based on a 50,000L pool (and depending on the strength & quality of algaecide) a dose of 250-500ml per month should suffice. Some products on the market contend that a dose will last 3 months. In our opinion, monthly dosing is preferred.