Why Have I Got Sand In My Pool?

26 May

If your pool filter is blowing sand into the pool, it almost certainly means there’s an internal problem with your sand filter—specifically, damage or failure of the components that are supposed to contain the sand inside the filter tank.

🔧 Main Causes of Sand in the Pool (From the Filter)

✅ 1. Broken or Cracked Laterals

The laterals are small, slotted plastic "arms" at the bottom of the filter that keep sand in while allowing water to pass.
If one or more break or crack, sand escapes into the return lines and ends up in the pool.
Most common cause of sand leakage.

✅ 2. Standpipe or Diffuser Damage

The standpipe (the vertical pipe in the center of the filter) could be cracked or loose.
A broken or misaligned diffuser (at the top) may cause water flow to disturb the sand bed, pushing sand into the pool.

✅ 3. Wrong Sand Type or Overfilling

Using sand that’s too fine or not made for pool filters (e.g., play sand) can lead to it passing through the laterals.
Overfilling the filter with sand can also push sand into the return line.

✅ 4. High Water Flow

If your pump is too powerful for the filter, it can churn up the sand bed and force sand through undamaged laterals.
This usually happens more gradually and is less common.

🛠️ How to Fix It

1. Turn Off the Pump Immediately

To prevent more sand from entering the pool or damaging equipment.

2. Inspect the Filter

Open the filter tank (usually by removing the top dome or clamp).
Carefully remove the sand (a wet/dry shop vac helps).
Examine:
- Laterals: Check for cracks or breaks.
- Standpipe: Inspect for cracks or poor fitting.
- Diffuser (if present): Look for damage or misalignment.

3. Replace Damaged Parts

Replace broken laterals, standpipe, or diffuser as needed.
If the filter is very old or multiple parts are cracked, a new filter assembly might be more cost-effective.

4. Add Proper Filter Sand

Use #20 silica sand or sand specified by the manufacturer.
Fill only to the level recommended (usually about 2/3 full).

🧼 Cleaning Up Sand in the Pool

Use a manual vacuum (not robotic) to remove sand from the bottom.
Vacuum to waste if possible so you don't run it back through the filter.
You may need to vacuum a few times as some sand may settle again.

Give Micks Pool Care a call and we can assess your filter and see what the best way forward may be.

Michael Ryan