How to change the filtration sand or glass grain of a sand filter

Spring is the perfect time to take care of your sand filter. Despite the name, filter glass is used instead of sand, as it has superior filtration capacity. 

Ideally, change the filter glass every three to five years. You can do it more often, especially if the water in your pool is having trouble staying filtered and clear. 

But why should you do it in the spring? Because the plumbing is not connected yet and the filter is already empty. Still, you can do it at any time, even in mid-season. 

Before starting, close the pool pump and remove the drain plug to allow the water to flow. In the spring, these steps are already done. Remove the collar from the filter’s head and lift the head. 

Empty the filter glass with a workshop vacuum or do it by hand by tilting the filter on the side. It will just take a little longer. 

Inside, you’ll see the lateral assembly. The laterals are the finger-like tubes at the end of the center pipe. You’ll need to fold or unscrew them to remove the assembly. Take this opportunity to inspect the center pipe to ensure there are no cracks. If this is the case, the filter glass could seep into the lateral assembly. 

When everything is clean, replace the drain plug and fill the filter with water up to half its capacity to avoid damaging the lateral assembly when pouring the filter glass. The water will absorb the shock. Then, put the assembly back, unfolding or screwing the laterals one by one. The assembly must be centered in the filter. If you are two, one person can plug the center pipe while the other pours the filter glass. If you are alone, use tape to prevent the glass from seeping into the center pipe. Once the filter glass has been poured, put back the head and screw on the collar to close the filter. 

These are simple steps to ensure that you’ll have good filtration for at least another three to five years. 

When you go to the store to buy filter glass, write down the information on the label, or even better, take a picture of it. It will help us determine the right amount of filter glass to refill your filter.