Keeping your swimming pool filters properly serviced is the key to having clean, healthy, sparkling water in your pool or spa. The best way to determine that your pool filter needs service is to watch the pressure. When the pressure rises 8 to 10 psi above the baseline it is time for pool maintenance. Cloudy water is another sure sign that your swimming pool filter needs maintenance.Safety should always be the first consideration when replacing or cleaning your swimming pool filter, especially those filters that are fitted with pressure-clamps. These pressure-clamps can “blow” under certain circumstances, causing property damage, severe injuries and in the worst cases, death.