The water in your pool is important to keep clean and fresh, but why does your pool’s water start to drain when you first turn on the filter? Most filters include a water drain to help with this particular issue.
Since dirt and debris are removed from the water as you wash it down with your garden hose, you’ll know exactly when you need to change the filter. But many times this isn’t apparent. This is because different water conditions cause the leak in different ways. To understand this, let’s take a dive into the science behind why pool filters start leaking when they’re first turned on.
How Fluid Fits Inside The Filter
You’ll have to decide how much fluid you need inside the filter for your pool. This is largely determined by the size of your pool and how often you use it. The amount of fluid determines how easily the dirt and debris can be washed down with your water. Remember, a higher volume of water will require a bigger filter. In most cases, one gallon will do just fine for typical homes with average-sized pools.
Once you know how much fluid you need, you’ll have to decide how you want to handle the overflow. Some filters are designed so that when more water enters the system than will fit inside the filter, it’ll back up and out through a vent. But you’ll still be able to use the pool. Others will become completely choked and don’t allow any water to flow at all, requiring replacement.
Why Does The Filter Need To Be Re-Filled?
After your initial fill, the filter will still need to be re-filled. The reason for this is twofold. First, the filter will become saturated with minerals and chemicals that enter the water from the pool itself. These elements will either slow down or entirely close off the pores in the filter material, preventing the filter from functioning as well as it could. Second, the water that drains from the pool will include some dirt and debris, which will eventually clog up the filter with enough force to prevent efficient water filtration.
As you use the pool and the water becomes dirty, the minerals and chemicals will accumulate on the outside of the filter. This is why it needs to be cleaned at regular intervals with a garden hose or similar device. But even after you’ve cleaned it, the filter will still need to be re-filled before you use the pool again. With any luck, this process will only need to be done once or twice a year at most.
Is It Worth The Trouble?
When you’ve tried to use a filter with a slow-drain design, you’ll know exactly what we mean. Since the water will be slowly trickling out, you may not even notice that the filter is starting to clog up until it’s already too late and you have to resort to manually flushing it clean or replacing it altogether. In some cases, this can be a very laborious process, especially if you have to go under the house or in between rooms to reach it. But you’ll be better off having the filter replaced annually or every other year in most circumstances, rather than risking malfunction by using a clogged filter.
Manual flushing can also be very dangerous, as you’ll be directly handling the flow of potentially dangerous water while trying to clear the filter’s drain. This is why we recommend against its indiscriminate use and instead suggest that you use a vacuum cleaner to suck up all the water that has collected inside the filter (see our cleaning tips here). But if you really want to avoid any accidents, you should change the filter at least once a month to ensure that adequate fluid is flowing inside it and that there aren’t any blockages preventing water from reaching the pool’s drain.
At the end of the day, it’s all about knowing what constitutes as normal operation of your particular pool. For some, running the filter for a couple of weeks without incident may be enough to justify the effort, whereas others may need to switch to a much larger filter to ensure that they don’t experience any performance issues. Your own pool’s characteristics will determine how you want to handle this situation, and how often you need to change the filter. Keep this in mind and you’ll know exactly when you need to clean or replace it.