Choosing a Canister Filter for 55-gal Saltwater — OASE Biomaster Thermo 600 vs EHEIM Classic

Andrés Garza

New member
Hello Reefers,

I have a 55-gallon (≈200 L) saltwater aquarium (fish-only) and I am evaluating external canister filters. My shortlist:

• OASE Biomaster Thermo 600
• EHEIM Classic (92-gallon rated)
• Also considering: Fluval 407, Penn Plax Cascade 1200, and SunSun (though I find fewer reviews for these).

I’d appreciate your technical feedback and real-world experience, especially if you’ve used any of these in a marine setup.



1. Actual flow vs rated flow: Does the model maintain its advertised flow after adding media and hoses? Any noticeable flow loss over time due to airlocks or impeller wear?

2. Media volume & layout: How many liters or baskets does each canister hold? How easy is it to customize media (bio / chem / mechanical)?

3. Prefilter or mechanical stage: Is there a removable prefilter that can be cleaned without opening the entire canister (like the OASE tube-style prefilter)?

4. Priming and air handling: How reliable is the self-priming? Any issues with trapped air, gurgling, or needing to re-prime frequently?

5. Materials & saltwater compatibility: Any corrosion problems (metal clips, springs, seals) or plastic parts that degrade in marine conditions?

6. Noise & vibration: Subjective impressions or noise comparisons between these models.

7. Maintenance ergonomics: How easy is disassembly, cleaning the impeller, replacing seals, etc.? How long does a typical maintenance take?

8. Longevity & reliability: How long have yours lasted? Any recurring issues (impeller shaft, motor, o-rings)? Are spare parts easy to find?

9. Performance in marine systems: If you’ve used them on fish-only or reef setups, was the flow adequate or too strong/weak for certain livestock?

10. General recommendation: For a 55-gal saltwater aquarium, would you choose a filter rated near that volume or oversize it? By how much?

---

My main decision is between the OASE Biomaster Thermo 600 and the EHEIM Classic (92-gallon rated), but I’m open to input on the Fluval 407, Penn Plax Cascade 1200, and SunSun.

Thanks in advance for sharing yo
ur experiences and technical feedback!
 
Back
Top