Water type
Marine + Reef
Fits
Red Sea ReefMat 250
Part no.
RED852a
Replace every
2 months
Size
32 m x 8 cm roll
Media type
Non-woven polyester fleece
Red Sea ReefMat Fleece Mat 250
Genuine replacement fleece for the ReefMat 250. This is Red Sea's own replacement roll for the ReefMat 250 automatic roller filter – the correct width and material grade to load straight into the unit and keep continuous mechanical filtration running once the current roll is spent.
Key features
- Correct fit, first time – sized specifically for the ReefMat 250; the 500 and 1200 use wider fleece and won't seat correctly in a 250.
- Non-woven polyester fleece – the same fine mechanical media grade fitted as standard to a new ReefMat 250.
- 32 m per roll – good for roughly 5–8 weeks on a moderately stocked reef system before the next change.
- Drops straight onto the dispensing shaft – no cutting or trimming to width.
Specifications
| Fits | Red Sea ReefMat 250 |
|---|---|
| Roll width | 8 cm |
| Roll length | 32 m |
| Material | Non-woven polyester, approx. 50 g/m² |
| Typical roll life | Roughly 5–8 weeks on a moderately stocked reef |
| Manufacturer part number | RED852a |
Which roll do I need?
| Filter unit | Fleece roll needed | Roll width |
|---|---|---|
| ReefMat 250 | This roll (RED852a) | 8 cm |
| ReefMat 500 | ReefMat 500 fleece roll | 11.3 cm |
| ReefMat 1200 | ReefMat 1200 fleece roll | 17 cm |
The three widths aren't interchangeable – a roll cut for the 500 or 1200 won't seat correctly on a 250's narrower dispensing shaft. Check your unit's model before ordering.
Suitable for, and not suitable for
Suitable only as a replacement for the Red Sea ReefMat 250. Not compatible with the ReefMat 500 or 1200, and not a fit for other brands' roller filters – Red Sea's dispensing mechanism and shaft width are specific to the ReefMat range.
Goes well with
Keep a spare roll on the shelf rather than waiting on the ReefBeat app's low-roll alert – a filtration gap while a delivery is in transit is the one situation the alert can't prevent. A spare ReefMat power supply is worth keeping on hand for the same reason.
Warranty and delivery
As a consumable filtration media, this roll isn't covered under Red Sea's equipment warranty. Standard parcel delivery applies.
Common questions
Will this fit my ReefMat 500 or 1200?
No. Each ReefMat size uses a different fleece width – this roll is cut specifically for the ReefMat 250's 8 cm dispensing shaft.
How long does one roll last?
Roughly 5–8 weeks on a moderately stocked reef system. Heavier bioloads or bare-bottom tanks use fleece faster; the ReefBeat app tracks your unit's actual usage and gives advance notice before the roll runs out.
Can I cut a wider roll down to fit the 250?
Not recommended – the dispensing and take-up shafts are matched to each model's specific width, and a cut edge can fray and jam the mechanism.




