Dolphin not picking up dirt or debris

dolphin

Double-check before purchasing

Filter basket dimensions and access procedures vary by model — verify your specific model before purchasing replacement parts.

The Problem

When your Dolphin completes its cycle but the pool is still dirty, the cause is almost always the filter, the impeller, or how the robot is being lifted out. The robot is moving — it just is not capturing what it vacuums up.

Steps

1
Remove the filter basket and inspect it. If it is more than half full, clean it. Hold it up to light — if you cannot see through the mesh, replace it.
2
Check that the filter is correctly seated and the access lid clicks fully closed with no gaps.
3
Flip the robot and inspect the impeller cavity. Use scissors to cut away any wrapped hair or roots on the impeller shaft.
4
Examine the brushes. Flattened bristles or worn rubber fins mean debris is not being scrubbed loose. Replace brushes if worn.
5
At end of next cycle, lift the robot out slowly and keep it level as it clears the water surface.
💡 Use the caddy or tow hook where possible — it keeps the angle consistent and keeps debris inside the basket.

Possible Causes & Solutions

common

Filter basket is full, torn, or incorrectly seated

Remove and inspect the filter. A basket more than half full cuts suction significantly. A torn mesh lets debris pass straight through. A poorly seated filter creates a bypass gap.

common

Impeller clogged with hair or debris

Open the filter compartment and check the impeller cavity. Hair and fine roots often wrap tightly around the impeller shaft and restrict flow without being visible from the outside.

common

Robot lifted out too fast, dumping debris back into pool

Lift the robot slowly and keep it level as it clears the water. Tilting it or pulling it out fast causes collected debris to pour back out of the filter.

occasional

Worn brushes not agitating debris off the pool surface

If bristles are flattened or rubber fins are worn thin, the robot moves over debris without scrubbing it loose for the suction system to capture.

occasional

Filter access panel or lid not fully sealed

Even a small gap in the filter housing lets water bypass the filter entirely. Ensure the lid or access panel clicks fully closed after each cleaning.

When to Replace

Replace filter bags or cartridges when mesh shows tears or permanent deformation. Replace brushes when bristles are worn to less than half their original length.

Where to Buy

Find compatible replacement parts from these retailers:

Check price for dolphin replacement parts on Amazon

Compatible Parts

Dolphin Replacement Filter Basket (Fine Mesh)

Check your model — E10, M400, M600, and Nautilus CC all use different basket sizes.

Dolphin Replacement Filter Basket (Ultra-Fine)

Use for pools with algae, fine sand, or dust. Requires more frequent cleaning than standard mesh.

Dolphin Replacement Brush Set

Available in standard and fine-thread variants. Brush mount type varies by model.

Frequently Asked Questions

How often should I clean the Dolphin filter?

After every cleaning cycle. Even a partially full filter reduces suction significantly. Rinse with a garden hose until the water runs clear.

My filter looks clean but the robot still leaves debris. What else could it be?

Check the impeller for hidden clogs. Hair and fine roots wrap tightly around the shaft and restrict flow without being obvious from the outside.

Should I use fine or ultra-fine filter cartridges?

Use standard fine filters for leaves and larger debris. Switch to ultra-fine for sand, pollen, or algae. Ultra-fine filters clog faster, so clean them after every single cycle.