Oase Biomaster Thermo 600

An external filter with integrated heater

The BioMaster range is available in two versions: with or without a heater. On the Thermo models, the HeatUp heater is housed inside the filter. The result: no more visible heater in the aquarium, an unobstructed view of the décor and fish, and heat distributed by the water flow coming out of the filter.

The 600 model is at the top of the range. The product sheet presents it as ideal for aquariums from 250 to 600 litres, in both freshwater and saltwater. For a smaller aquarium, the 250 and 350 versions are more suitable; for a larger tank, the BioMaster 850 Thermo takes over.

How does it work?

The BioMaster follows a proven principle: separate the retention of large debris from biological filtration, so that the latter remains effective for a long time.

• The EasyClean prefiltration chamber retains most of the particles. It can be cleaned without dismantling the entire filter, which prevents disturbing the biological mass.
• The filter sponges refine the mechanical filtration.
• The Hel-X media provide a large surface area for the bacteria that convert ammonia and nitrites. This is the biological heart of the filter.
• The HeatUp heater, on the Thermo version, warms the water before it returns to the aquarium.

The filter also features an automatic shut-off mechanism and a safety lock, which prevent water from flowing out when removing the prefiltration module, as well as a purge button for easy startup.

For which aquariums?

The BioMaster Thermo 600 is well suited for:

• medium to large community aquariums, between 250 and 600 litres;
• tropical freshwater tanks, where the integrated heater frees up space in the décor;
• marine aquariums, compatible according to the product sheet;
• aquarium enthusiasts who want to space out and simplify maintenance.

For a cold-water aquarium (e.g., goldfish), the version without a heater, the BioMaster 600, is more logical.

Installing the BioMaster Thermo 600

The complete kit includes the filter media, the hose, an adapter, the suction and discharge pipes, and a water diffuser. Installation is done in a few steps:

1. Place the filter under the aquarium, in the cabinet, on a stable surface. The maximum indicated water column height is 1.80 m.
2. Cut the hose to the correct length for suction and return, without unnecessary loops or bends.
3. Install the suction screen on one side of the aquarium and the outlet on the other, so that the water circulates throughout the volume.
4. Fill the filter using the purge button, then check for leaks at the connections.
5. Plug in the filter then set the desired temperature, checking with a thermometer after a few hours.

Daily maintenance

The BioMaster's asset is its prefiltration chamber. It concentrates most of the dirt: this is the one you will clean most often. The biological mass (Hel-X) should only be rinsed occasionally, and always in aquarium water, to preserve the bacteria.

• Clean the prefilter as soon as the flow rate drops significantly.
• Rinse the sponges in a bucket of aquarium water, never in hot tap water.
• Check the condition of the gaskets and lubricate them if the manual provides for it.
• Replace the sponges when they become deformed.
• Avoid cleaning the filter on the same day as a major water change.

If the rotor becomes noisy due to limescale deposits, clean it with a dedicated product such as OASE PumpClean, then rinse thoroughly before reassembling the part.

Integrated heater or separate heater?

The question comes up often: is it better to have a filter with an integrated heater or a classic filter combined with a heater in the aquarium? Both solutions work, and each has its arguments.

• The integrated heater frees up space in the aquarium, removes a visible cable, and prevents large fish from huddling against a heater. The heat is diffused by the filter's outlet flow, which helps to homogenize the temperature.
• The separate heater allows you to replace a single element in case of failure and freely choose its power. However, it remains visible in the décor, unless hidden behind plants or rocks.

With a Thermo filter, keep in mind that the water must circulate for the heat to reach the aquarium. During prolonged maintenance, unplug the entire unit, and check the temperature once the filter is restarted.

Questions to ask before buying

Before ordering, take a few minutes to check that this model is well suited to your setup:

• Is the actual volume of your aquarium, décor deducted, within the range of 250 to 600 litres?
• Does the cabinet offer the necessary space for a 240 x 240 x 480 mm filter, with easy access to the prefilter?
• Do your fish need heated water? If not, the version without a heater is sufficient.
• Have you planned the starter bacteria and a water test for startup?
• Will the current suit your fish, or will you need to plan a softened outlet?

If several answers make you hesitate, a smaller model from the range or personalized advice will prevent you from making an unsuitable purchase.

Our tips to get the best out of it

• Seed the filter at startup with aquarium bacteria and test the water before introducing all the fish.
• Set the water outlet according to your fish: a diffuser pointed towards the glass or a ramp softens the current.
• Monitor the temperature in summer: the heater does not cool the water. Our article how to cool an aquarium helps you in case of heat.
• Keep a set of replacement sponges so you don't have to wait for a delivery at the time of maintenance.

Finally, write down the date of each maintenance in a small notebook or on your phone. After a few months, you will know the ideal pace for your aquarium: it depends on the population, the food distributed, and the plants, and no standard calendar can replace it.

To go further on volumes and flow rates, read our article what filtration flow rate for an aquarium.

Frequently asked questions

For what aquarium volume is the BioMaster Thermo 600 made?

The product sheet indicates aquariums up to 600 litres, and presents it as ideal for volumes of 250 to 600 litres.

What is the difference between the BioMaster 600 and the BioMaster Thermo 600?

The Thermo model integrates a 300 W HeatUp heater in the filter. The BioMaster 600 offers the same filtration, without a heater.

Is the BioMaster Thermo 600 suitable for saltwater?

Yes, the product sheet lists it as compatible with freshwater and saltwater.

What hose diameter does it use?

The connections are designed for a hose with an inner diameter of 16 mm and an outer diameter of 22 mm.

How often to clean the filter?

Clean the EasyClean prefilter as soon as the flow rate drops. The biological mass is only rinsed occasionally, in aquarium water.

Should bacteria be added at the start of the filter?

It is recommended. Aquarium bacteria help the Hel-X media to colonize faster. Then test the water, especially nitrites, before gradually introducing the fish.

Also read

• Understanding the filtration mechanism in an aquarium
• Where to place the heater in an aquarium?
• How to properly maintain your aquarium?