OASE BioMaster 2 Thermo 250 Canister Filter for Aquariums – External Aquarium Filter with Built-in Heater – EasyClean Pre-Filter, Quiet Operation – Freshwater & Saltwater, Up to 70 Gallons

I picked up the OASE BioMaster 2 Thermo 250 Canister Filter for my aquarium, and overall it’s been one of the best all-in-one filtration solutions I’ve used, especially for tanks where space and simplicity matter. Right away, the built-in heater integration stands out. Instead of running a separate heater with suction cups and extra cords, this unit heats and filters in one streamlined system. It keeps the temperature stable without hot spots, and the layout looks much cleaner than having multiple devices inside the tank. For anyone who cares about aesthetics and functionality, that combination alone is a huge win. In terms of filter performance, this unit moves water efficiently and handles biological, mechanical, and chemical filtration well. The flow rate is strong without being too aggressive for most community tanks, and the water always looks clear and healthy. I’ve noticed fewer maintenance intervals compared to simpler hang-on filters — the media inside has plenty of capacity and is easy to access when it’s time for a clean. Installation was fairly straightforward. The hoses and connections are solid, and the instruction layout made sense. Once set up, the unit runs quietly and reliably — it doesn’t dominate the room with noise. things to note: The initial price is higher than a standalone filter + heater combo, but in my opinion the integration and convenience justify it. Overall, this OASE BioMaster 2 Thermo 250 feels like a top-tier choice in canister filtration with the added bonus of heating built in. It simplified my setup, performs strongly, and keeps my aquarium water looking great with less fuss — definitely one of the best options I’ve used for mid-size tanks.

I bought this a few days ago. It is super quiet extremely quiet. I have to say everything works perfectly. Although having some heater issues, nothing serious. But I think I have increase the temperature to the above the desired temperature or perhaps I just haven’t waited long enough but all in all it’s excellent

Everything I asked for

I am writing this review after only 4 months of owning this canister filter. We have had nothing but issues with it. First after 2 months the heater stopped working, so had to buy a replacement (which we did not by an Oase) we bought an heater that sets in the tank. Then in September the 4th the whole thing just quits. No suction at all. Took it apart and cleaned it, which it had been cleaned just a month earlier. Check the impeller. We did everything and nothing we did fixed it. I don't know if we are just the unlucky folks who got a bad unit. I guess our only option is to contact Oase customer service and hope they will actually take the unit and fix it. OR send us a new unit to replace this one. Lot's of money down the Aquarium drain at this point :(

I have a 65 gallon freshwater tropical tank. It's been setup for 10+ years at this point, and I previously ran a pair of Fluval (AuqaClear) 70's on it. I grew tired of the noise and the continuous maintenance. Decided on this Oase BioMaster, mainly because it was one of the few canister filters that would fit inside my cabinet under the tank. I am absolutely shocked at how quiet this thing is! It is absolutely silent. It's been up and running for about a week at this point, and so far, so good! Assuming this works as well as I've heard it does, I'm never going back to my HOB filters. Setup was easy, once I learned about the trick of heating up the tubing first. doing that allowed it to fit where it needed and when it cooled, it formed a watertight seal. Fingers crossed that this lasts as long as I think it will!

This thing is SILENT! I’ve had cascade canisters for years. Bought a couple new one and they’re so loud. Oase is my go to now

I’ve had it for almost about a year now and up until recently It was doing just perfectly. But now it’s having these bouts of low power and kind of a loud clicking noise. Just keep that in mind. Mine might just be special.

I bought this filter to help with filtering and heating a 20 gallon tall (UNS 60U) aquarium. Though I fought with cleaning the pre-filter and internal sponges within the canister filters on numerous occassions, at the almost month mark I was so fed up that I returned the filter. It really was doing a poor job of cleaning my heavily planted 20 gallon aquarium as it left the water consistently murky. The outflow was also way too strong and caused a strong current even when turned down all the way (almost like a powerhead). When I switched back to a sponge filter the tank was clear overnight. The heater that came with this filter also failed on multiple occasions. After the third time, I yanked it out and returned to a bulky filter that had to be placed into the tank. One of the main reasons I bought this item was to have more space for aquascaping my tank by removing the heater, so this was especially frustrating. The reason I'm leaving 2 stars is because I've heard from other forums/videos/sources that this filter CAN be good for larger aquariums. I'm not sure how that maths out, but I doubt this narrative would exist without some happy customers perpetuating it.

This was my first time using an external filter and after all my research this was my best opinion. Low maintenance and takes up less space and super quiet

Work of art!