How often should I replace my Brita filter to ensure the optimal functionality and longevity of my water filtration system? Isn’t it imperative to consider not just the frequency but also the specific circumstances that might necessitate more regular replacements? For instance, do factors such as the quality and hardness of your tap water, the volume of water you typically consume, and even the presence of contaminants influence the lifespan of the filter? Moreover, is there a universal guideline that all brands or models adhere to, or do they vary significantly in their recommendations? Shouldn’t I also be vigilant about signs that indicate a filter’s decline, such as a noticeable change in water taste or odour? Additionally, how does seasonal variability affect filter performance? Could it be worth consulting the manufacturer’s instructions for tailored advice, or are there reliable general rules based on extensive user experiences? What should I keep in mind to ensure the health and safety of my drinking water?