why is my pool filter blowing out sand
Pool Knowledge

Why Is My Pool Filter Blowing Out Sand?   

It is common for your sand filter to blow out the sand into the pool. If you find yourself asking: why is my pool filter blowing out sand? Then the direct answer shall be that your filter is broken up. The detailed answer shall be that a specific part of your sand filter is broken up. Most at times, when the lateral pipe breaks or cracks, your filter shall start blowing out the sand into the pool water. 

A lateral is the series of pipes below your filter that filters out the water leaving your collectors sand in the tank. Other parts of the filter might have a hitch leading to this problem. Whatever the issue might be, you can fix it or have it professionally fixed in a few hours. This is how to do it.

Why Is My Pool Filter Blowing Out Sand – How the Filter Functions   

A pool sand filter is a type of water pool filter that uses sand to filter out foreign particles and dirt from the pool water. It is designed with an inlet pipe on the top which connects to a tank. The tank is filled with coarse pool sand. At the bottom is a perforated outlet that filters out the cleaned pool water leaving out the sand. The filtered water is then pumped back into the pool. One of the parts of this sand filter might break up releasing the sand in the tank into the pool. 

Let’s Understand the Filter  

A filter includes eight or six pipes fixed laterally at the bottom of your filter. These pipes are perforated to hold back sand and allow only water into the return pipe. In case one or all of these pipes break up, they shall release the held-back sand into the return pipe which shall let out the sand into your pool. 

The seal might also break and lead to sand getting into your pool water. The seal is usually located between the multiport connection and the standpipe. The seal is made using a washer that wears out thereby breaking the seal.

Why Is My Pool Filter Blowing Out Sand?   

We, therefore, realize that the possible causes of sand blowing out of your filter are: 

When the lateral pipes have a crack and start releasing sand into your standpipe. 

When your standpipe breaks, this is not so common due to the strength and thickness of the standpipe.

When your seal is worn out and therefore releases sand from the tank into your pool water.

Why Is My Pool Filter Blowing Out Sand? How to Correct It   

As you can guess, the solution here is getting these breakages corrected and the seal replaced. However, it isn’t that simple, you shall have to remove the filter and completely disassemble it to locate the problem area. You shall also need fresh sand to fill your filter tank after the repair process. Endure that you get the right pool filter sand from a supplier, the amount here shall depend on the size of your filter tank. 500-700 pounds usually work for most big tanks.

If you realize that the laterals are the ones with a problem, you shall have to buy a new set. Filters differ in terms of the laterals they use. The best thing to do is bring out your manual and check what king of laterals shall work for your filter type. Order or physically go and purchase this new set.

If the washer or the O-ring is the problem, you have to replace it. Take the worn-out washer with you when going to buy a replacement, this way, you shall buy the correct one.

Why Is My Pool Filter Blowing Out Sand? – The Repair Process  

Here is a step by step guide on how to repair a filter that is blowing out the sand into your pool.  

Prepare to remove the filter  

Stop your pool water circulation system to stop water from getting into your filter. After this, drain any water already in your filter, to do this, open the draining screw at the bottom of your filter. Water shall drip out of your filter, wait until it drips completely then proceed.

Unscrew unions and the collar  

The next step is letting free your filter. Open the collar of your pool sand filter. Unscrew the connections that connect your filter to the pool water circulation system. If your installation did not include unions, you might have to cut the pipes, it is advisable that you include unions later when replacing. Unions ease the work during disassembling.

Detach the multiport assembly and empty the sand 

Carefully detach the multiport assembly from your system. Immediately you detach, cover your standpipe to avoid getting sand into it. You can use duct tape or any other appropriate material. Now, vacuum out all the sand from your filter pump. You shall need a dry/wet vacuum for effective sand vacuuming. This process shall take a while but it’s necessary and you shall have to wait.

Remove the laterals and check for cracks 

Exercise extra caution when searching the laterals from the standpipe. After you have them, carefully check for any cracks and do a replacement for each. If you are not sure whether your laterals are cracked, it is good that you just replace them to be sure. After this, counter check your standpipe to discover a crack, it is not easy for this pipe to crack, however, there is a possibility. Therefore, check to be sure and replace it in case of any cracks.

Start the return process  

Slowly attach the manifold to your filter. Adjust your laterals to sit laterally in your filter. After this, connect the standpipe to your laterals. Now, half fill your filter system with water for the protection of your laterals against the sand.

Correct and return the collar, your washer, or the O-ring 

If your washer or O-ring is worn out, be sure to replace it when reassembling your filter system. Attach your multi-port assembly to your standpipe and screw up the collar. Screw all the unions that hold your filter system to your pool water circulation system. The new sand shall require that you backwash your filter to clean it up.

Why is my pool filter blowing out sand? Well, the above are the reasons and correctional remedies.