The Oase BioMaster² Thermo is one of the most advanced external filters on the market, designed to combine powerful multi-stage filtration with the convenience of an integrated heater. Whether you’re setting up your first canister filter or upgrading from a different brand, this step-by-step guide will help you install your BioMaster² Thermo correctly, keep it running efficiently, and make future maintenance quick and easy.
Why Choose the BioMaster² Thermo?
Before diving into the setup, let’s quickly recap what makes the BioMaster² Thermo a standout choice:
- EasyClean pre-filter: Removes for cleaning without opening the canister.
- Integrated HeatUp heater: Eliminates the need for a separate in-tank heater.
- Hel-X biological media + sponges: Delivers effective mechanical and biological filtration.
- Improved design: The BioMaster² offers 25% higher flow rates than the original BioMaster and enhanced ergonomics for easier handling.
- Quiet, efficient operation: Ideal for both freshwater and saltwater aquariums.
What You’ll Need
- Oase BioMaster² Thermo filter (in the correct size for your tank)
- All included filter media (sponges, Hel-X, heater module if not pre-installed)
- Hoses, adapters, and suction cups (included in the box)
- Bucket of aquarium water for rinsing media
- Towels or cloths for setup area
Step 1: Unbox and Inspect Components
- Remove the filter, hoses, and accessories from the box.
- Check that all parts are present: canister, pre-filter, media baskets, heater (if Thermo version), hose sets, clips, and suction cups.
- Ensure no plastic or transport plugs are left in the canister.
Tip: Keep the instruction manual nearby—Oase provides useful diagrams for hose routing.
Step 2: Prepare the Filter Media
- Open the canister and remove the media baskets.
- Rinse the sponges and Hel-X media in dechlorinated water or old tank water (never under the tap).
- Load baskets in the recommended order:
- Bottom: coarse sponges (trap large particles)
- Middle: Hel-X biological media (provides surface area for bacteria)
- Top: fine sponges or optional chemical media
Tip: The modular baskets make it easy to adjust filtration later. For planted tanks, consider adding peat or phosphate remover.
Step 3: Install the Integrated Heater (Thermo Models Only)
- Insert the HeatUp heater into the designated Thermo slot.
- Lock it securely in place following the arrows on the housing.
- Set the desired temperature on the heater dial.
Why it matters: The heater will now warm water as it circulates, distributing heat evenly throughout the tank.
Step 4: Connect the Hoses and Intake/Outflow
- Measure and cut hoses to the correct length—avoid sharp bends.
- Attach the intake pipe and spray bar or outflow nozzle with suction cups.
- Secure hoses to the filter head, ensuring they click into place with the quick-release adapters.
Tip: Keep hose runs as short and straight as possible for maximum flow efficiency.
Step 5: Prime the Filter
- Fill the canister and intake hose with aquarium water.
- Use the priming button (where available) or siphon action to start water flow.
- Check that water fills the canister and flows smoothly without air bubbles.
Step 6: Power On and Test
- Plug in the filter and heater.
- Observe for 5–10 minutes:
- Check for leaks around hose connections and O-rings.
- Ensure water is flowing steadily from the outlet.
- Listen for smooth, quiet operation.
Tip: A slight hum or initial gurgle is normal as trapped air escapes. Tilt the filter gently to release air pockets.
Step 7: Adjust and Fine-Tune
- Position the outflow just below the water surface for optimal circulation.
- For planted tanks, minimize surface agitation to reduce CO₂ loss.
- For community or marine tanks, increase agitation for better oxygenation.
Maintenance Schedule
The Oase BioMaster² Thermo is designed for low-hassle upkeep thanks to its EasyClean pre-filter.
- Every 2–4 weeks: Remove and rinse the pre-filter sponges.
- Every 6–10 weeks: Open the canister and gently rinse biological media in old tank water.
- Every 6 months: Inspect impeller, seals, and hoses; apply aquarium-safe silicone grease to O-rings.
Troubleshooting Common Issues
- Reduced flow: Check and rinse the pre-filter first—it usually solves the problem.
- Noisy operation: Ensure hoses are filled with water; tilt filter to release trapped air.
- Leaks: Re-seat O-rings and check quick-release fittings for secure locking.
- Heater not working: Confirm correct installation in Thermo slot and verify power supply.
Final Thoughts
Setting up the Oase BioMaster² Thermo might take a little more time than a hang-on-back or internal filter, but the payoff is huge: cleaner water, healthier fish, and easier long-term maintenance. With the integrated heater, modular media, and hassle-free pre-filter system, you’ll spend less time elbow-deep in your tank and more time enjoying it.
Ready to get started? Browse the full range of Oase BioMaster² Thermo filters at Charterhouse Aquatics and find the perfect model for your aquarium.
