--- product_id: 363994140 title: "BioMaster Thermo External Filter with Built-in Heater for Aquariums up to 70 gallons, Multi-stage Filtration, Easy Maintenance Prefilter, Quiet Canister Filter, German Engineering" brand: "oase" price: "€ 1442.92" currency: EUR in_stock: true reviews_count: 5 category: "Oase" url: https://www.desertcart.hr/products/363994140-biomaster-thermo-external-filter-with-built-in-heater-for-aquariums store_origin: HR region: Croatia --- # 250 GPH flow rate ultra-quiet operation 150W integrated heater BioMaster Thermo External Filter with Built-in Heater for Aquariums up to 70 gallons, Multi-stage Filtration, Easy Maintenance Prefilter, Quiet Canister Filter, German Engineering **Brand:** oase **Price:** € 1442.92 **Availability:** ✅ In Stock ## Summary > 🔥💧 Elevate your aquarium game with the ultimate all-in-one filter & heater! ## Quick Answers - **What is this?** BioMaster Thermo External Filter with Built-in Heater for Aquariums up to 70 gallons, Multi-stage Filtration, Easy Maintenance Prefilter, Quiet Canister Filter, German Engineering by oase - **How much does it cost?** € 1442.92 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/363994140-biomaster-thermo-external-filter-with-built-in-heater-for-aquariums) ## Best For - oase enthusiasts ## Why This Product - Trusted oase brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Customizable Flow Control:** Adjust inlet and outlet flow rates to perfectly suit your aquarium’s unique ecosystem and fish species. - • **Quad-Stage Crystal Clear Water:** Biological, mechanical, chemical, and prefiltration work seamlessly for pristine, toxin-free aquatic environments. - • **Effortless Maintenance with EasyClean:** Removable pre-filter module simplifies cleaning, extending filter life and saving you time. - • **Whisper-Quiet German-Engineered Design:** Operate your aquarium in peace with a silent external filter crafted for high efficiency and durability. - • **All-in-One Precision Heating & Filtration:** Integrated 150W heater ensures stable, uniform aquarium temperature without sacrificing space or aesthetics. ## Overview The OASE Indoor Aquatics Biomaster Thermo 250 is a premium external aquarium filter with a built-in 150W heater, designed for up to 70-gallon tanks. Featuring a 4-stage filtration system—biological, mechanical, chemical, and prefiltration—it delivers crystal-clear water and optimal aquatic health. Its compact, German-engineered design offers adjustable flow control, ultra-quiet operation, and an EasyClean pre-filter for hassle-free maintenance. Perfect for marine and freshwater setups, it combines efficiency, convenience, and style with a 3-year warranty plus an optional 1-year extension. ## Description The biomaster Thermo line of premium external filters with integrated heaters are perfect for marine and freshwater aquariums. The biomaster Thermo 250 boasts 4-stage filtration in a compact design. With the heater integrated into your filter, there is more room for undisrupted beauty in your aquarium. Biological, mechanical, chemical, and prefiltration all work together to provide your aquarium with optimal water quality and clarity. The biomaster filters are designed with sealed filtration pathways to ensure water flow is getting the full benefits of prefiltration, filter media for clearer water, hel-x biomedia provide a large suspended settlement surface for microorganisms, and activated carbon for ideal nutrient reduction and removal of toxins. The easy clean pre-filter module can be removed and cleaned separately from the rest of the filter for high efficiency and to extend the life of your filter. The water flow Can easily be adjusted on both the inlet and outlet adapters for the filter. Created for convenient placement under the aquarium. Install the included diffuser and spray bar for uniform surface movement and additional dissolved oxygen for ideal water quality. This filter Also features a N handle for simple moving and maintenance. This energy-efficient design includes a self-priming function for easy operation on startup and after cleaning. Includes a shut-off automation with built-in check valve to prevent leakage when cleaning the filter. Designed using German engineering and manufactured in Italy, this quiet operating filter is supported by an included 3 year warranty with a free 1 year warranty extension with online product to customize your pre-filter by combining coarse, Fine, ultra Fine, and activated carbon filter foams. Review: Great aquarium filter! Review: Best Filter on the Market ## Features - The Bio master thermos 250 has an integrated heater in compact Filter design - The built-in heater provides your aquarium with Precise and uniform temperature levels while the product integration delivers unobstructed views of your Aquarium - External filter operates quietly to circulate and filter your aquarium water - Includes 4-stage filtration: biological, mechanical, chemical, and prefiltration - Hel-x, suspended Filter media, creates the optimal surface area for beneficial bacteria growth ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B07LHD941X | | Brand | OASE | | Brand Name | OASE | | Capacity | 70 Gallons | | Colour | Black | | Customer Reviews | 4.3 out of 5 stars 739 Reviews | | Efficiency | High | | Flow Rate | 250 Gallons Per Minute | | Global Trade Identification Number | 00706759551489 | | Heat Output | 150 Watts | | Included Components | Aquarium Filter with heater, filter media, tubing, intake and outflow tubes, diffuser, spray bar, fittings, and power cable | | Is Electric | Yes | | Item Depth | 14.6 inches | | Item Dimensions W x H | 23.9W x 37.1H Centimeters | | Item Type Name | Filter | | Item Weight | 11.46 Pounds | | Manufacturer | OASE | | Manufacturer Part Number | 55148 | | Material Type | Stainless Steel | | Maximum Pressure | 2.86 Pound per Square Inch | | Model Number | 55148 | | Mount Type | Wall | | Power Source | Corded Electric | | Product Dimensions | 23.9W x 37.1H Centimeters | | Special Feature | Adjustable flow control is built into the inlet and outlet of the filter, The EasyClean prefilter module can be removed separately from the rest of the filter for simple cleaning and to extend the life of your filter, The sealed filtration pathway allows you to get the full benefits from all 4-stages of filtration Special Feature Adjustable flow control is built into the inlet and outlet of the filter, The EasyClean prefilter module can be removed separately from the rest of the filter for simple cleaning and to extend the life of your filter, The sealed filtration pathway allows you to get the full benefits from all 4-stages of filtration See more | | Special Features | Adjustable flow control is built into the inlet and outlet of the filter, The EasyClean prefilter module can be removed separately from the rest of the filter for simple cleaning and to extend the life of your filter, The sealed filtration pathway allows you to get the full benefits from all 4-stages of filtration | | Style Name | Biomaster Thermo 250 | | UPC | 706759551489 | | Unit Count | 1 Count | | Voltage | 120 Volts | | Wattage | 165 Watts | ## Product Details - **Brand:** OASE - **Capacity:** 600 litres - **Colour:** Black - **Power Source:** Corded Electric - **Special Feature:** Filtration ## Images ![BioMaster Thermo External Filter with Built-in Heater for Aquariums up to 70 gallons, Multi-stage Filtration, Easy Maintenance Prefilter, Quiet Canister Filter, German Engineering - Image 1](https://m.media-amazon.com/images/I/71ooVApRXkL.jpg) ## Questions & Answers **Q: My unit is constantly purging air. Is there a solve for this issue? I recently bought mine just a week ago.** A: It is Amazing to me how Oase will not admit they have a problem with their Biomaster line . I have dealt with Douglas Ward ,President at Oase and Factory rep. Adam Raabe Aquatics Category Manager (North America) Both of them will not acknowledge there is a purging issue . If you look at the design of the filter you will find that whether it is the 250 or all the way up to the 850 they all use the same head unit all that is different is wattage and impeller . Foot print of the the whole biomasters is also the same except for height of canister . From my own personnel experience Biomaster 250 has no purge issues . Biomaster 350 for me purged from day one when I got it in 2019 .Biomaster 600 purged right from Day 1 and is still purging with new head unit and also larger diameter pre filter pipe with 3 times as many holes than stock . Also coarser pre filter sponges . If you look on line it looks like Biomaster 850 is even worse . Where I am going with this is that the whole basic design is built around dimensions of a lesser flow filter and there in lies the problem . All the silicone in the world on orings will not help the issue . When I took the impeller from the 350 and put it in the 600 head the purging lessened ,still there but less frequently . What I have found is the problem is cavitation inside the housing and trying to get more flow from the filter with the same basic dimensions is what is the cause . Simple hydraulics . Where the impeller sits inside the head is the same size no matter what biomaster you have ,I know this because I have the 250.the 350 and the 600. When you call oase they will try to tell you that is you put a pre filter sponge on the inlet tube in the tank it will cause a restriction and you will have purging BS!!! I am using a very fine sponge on the inlet tube of my biomaster 250 (it is in a shrimp tank) and I have let it go until that sponge was caked in mud and had NO purging ,even when I shook the sh!t out of the filter. The design of the Biomaster line is made for the 250 and the 250 alone . It's no secret there is an issue with that filter . I have an Ehiem 2217 since the 1970's and Two Fluvals 07 series . I have been in the hobby now for approximately 60 years and I have owned many filters over that time going back to the leather belt drive piston air pumps and the old Supreme hang on back filters ,I know something about filters. Oase knows they have a bad issue but does not know how to fix it without getting rid of the 350 ,600 and 850. To conclude here is a little tip ,get yourself a smart switch ,something like a Kasa . Set it up with a schedule where it switches off at least twice a day for a few minutes and comes back on . What will happen is that it will do a purge when it comes back on that will lessen the frequency of purging throughout the day . What you would be doing is what Fluvals FX built in feature does to purge built up air in filter . Unlike Oase Fluval needs only one on off per 24 hours . Smart switch will not cure problem but will lessen the purge issue considerably . **Q: hi I’m having trouble with this filter. It’s taking in air and it’s starting to make weird noises. who can I contact for warranty help? Thank you :)** A: Hello. We are sorry to hear that you are having an issue with your BioMaster Thermo 350. You may contact our Customer Care Team Monday through Friday between the hours of 8:00AM- 6:00PM ET. Our Team looks forward to assisting you! **Q: Does the heater have its own power source? In other words is it independent of the filter. I want to be able to hook the heater to a temp controller.** A: Hi, The built-in heater provides your aquarium with precise and uniform temperature levels with adjustable control. The heater is on a separate power cord from the filter. Hope this helps! **Q: does this come with activated carbon foam/media?** A: Hi, I purchased my biomaster thermo 350 1 year ago and has been running flawlessly ever since. Now, with the stock csrbon prefilters I had minimal purging.... So i switched to the blue 45 ppi and it was much better.... Then I purchase the red 30ppi and I guess 3 times is a charm... No more purging except the first 10 minutes after cleaning them... Then I am good to go for 3 weeks roughly and I will notice a slight decrease in flow and a few light purges which I've come to love. It's a simple reminder.... Hey, clean the prefilter. Do not listen to the ' gunk it with vasoline and buy metal hose clamps. I also have a second 350 and a 250 on my 15 gallon set up. My advice is really take your time conecting the hoses. I use clear hose and lily pipes... So I can't adjust the flow... Am going to get some double taps from oase now that they're available. Lastly, when I switched to the red 30 ppi pre's I notice avery dramatic increase in flow... Hopefully, this helps... I was kinda annoyed at even one purge when I first bought it... But, give it time... Carefully going over each connection. I use no lubricants of any type...just water from the tank... And all filtrrs are set up bottom tral blue stock sponge, all folling trays seachem matrix and top tray stock red foam. Only fill the trays about 3/4th with matrix. Don't stuff it in. The trays might sit uneven and cause issues .....anyway, best of luck... ## Customer Reviews ### ⭐⭐⭐⭐⭐ Great aquarium filter! *by M***B on 21 November 2025* ### ⭐⭐⭐⭐⭐ Best Filter on the Market *by F***D on 20 January 2021* ### ⭐⭐⭐⭐⭐ Best Canister I've ever owned *by J***N on 16 April 2023* ## Frequently Bought Together - OASE Indoor Aquatics Biomaster Thermo 250,Black - FZONE Aquatic Glass Lily Pipe Set with Skimmer Inflow and Outflow for Aquarium Filter 5/8''(16/22mm) Tubing - Seachem Matrix, 4 L / 1 gal. --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hr/products/363994140-biomaster-thermo-external-filter-with-built-in-heater-for-aquariums](https://www.desertcart.hr/products/363994140-biomaster-thermo-external-filter-with-built-in-heater-for-aquariums) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-04-27*