Product guide
Dolphin m400 filter bags
Double-check before purchasing
- Some regional M400 variants or older production runs may have used a different filter system — check your manual if the description does not match your unit
Compatibility
The Dolphin M400 does not use fabric filter bags — it uses rigid cartridge filter baskets. When M400 owners search for 'filter bags', they are typically referring to the mesh cartridge basket. Both fine-mesh and ultra-fine-mesh cartridge baskets are available for the M400.
How to Verify Fit
- The M400 filter is a rigid plastic-framed mesh basket — not a flexible fabric bag
- Two baskets are required per load — both must be installed and latched before use
- Confirm the product you are ordering is a cartridge basket, not a fabric bag intended for pressure-side cleaners like Polaris
Common Mistakes to Avoid
- Ordering fabric filter bags designed for pressure-side pool cleaners — these are a completely different product incompatible with the M400
- Confusion often arises when searching 'pool robot filter bag' — robotic cleaners use cartridge baskets, not bags
- Ordering M400 'filter bags' from listings that turn out to be generic fabric bags for suction or pressure cleaners
When to Replace
Clean both M400 filter cartridge baskets after every cleaning cycle. Replace the pair when mesh damage occurs — typically once per swimming season.
Buying Tips
Search for 'Dolphin M400 filter basket' or 'M400 filter cartridge' rather than 'filter bag' to find the correct product. OEM Maytronics and third-party compatible cartridge baskets are widely available.
Where to Buy
Find compatible replacement parts from these retailers:
Frequently Asked Questions
Does the Dolphin M400 use a filter bag?
No — the M400 uses cartridge filter baskets, not fabric bags. 'Filter bag' is sometimes used informally to mean the mesh basket, but technically they are different products.
What is the difference between a pool robot filter bag and a filter basket?
Pressure-side cleaners like Polaris use fabric filter bags to collect debris. Robotic cleaners like Dolphin use rigid mesh cartridge baskets. They are not interchangeable.
How many filter baskets does the M400 use?
Two — installed side by side in the top-load filter housing.
Still not working?
See our complete troubleshooting guide for all common issues:
Dolphin pool robot not working? Start here →