My unit is constantly purging air. Is there a solve for this issue? I recently bought mine just a week ago.

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 .

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 :)

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!

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.

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!

does this come with activated carbon foam/media?

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...

Desertcart Logo

Deliver to Cyprus

For best experience Get the App

DOWNLOAD THE APP

WE SOURCE ITEMS FROM

UAE
UK
India
USA
Japan
KOREA

Customer Services

About Us

Customer Support

Description

🔥💧 Elevate your aquarium game with precision heating and pristine filtration!

EFFORTLESS MAINTENANCE - EasyClean pre-filter module removes separately, extending filter life and simplifying upkeep.
CUSTOMIZABLE FLOW CONTROL - Adjust inlet and outlet flow for optimal water circulation and oxygenation tailored to your tank.
WHISPER QUIET PERFORMANCE - Energy-efficient, noise-minimized operation ensures a peaceful ambiance in your living or workspace.
SEAMLESS HEATING FILTRATION - Integrated 4-stage filter with precise temperature control for crystal-clear aquatic environments.
COMPACT GERMAN ITALIAN ENGINEERING - Space-saving design that maximizes aquarium visibility and elevates your aquatic aesthetic.

The OASE Indoor Aquatics Biomaster Thermo 250 is a premium external aquarium filter with an integrated 165W heater, delivering precise temperature control and 4-stage filtration (biological, mechanical, chemical, prefiltration) at a powerful 250 gallons per hour flow rate. Designed with German engineering and Italian manufacturing, it features a compact, quiet operation, adjustable flow control, and an easy-to-clean pre-filter module, making it ideal for maintaining crystal-clear water and a healthy aquatic environment.

Specifications

Manufacturer	OASE
Part number	55148
Item Weight	5.2 Kilograms
Product Dimensions	23.88 x 23.88 x 37.08 cm; 5.2 kg
Item model number	55148
Size	1 Count (Pack of 1)
Color	Black
Style	Biomaster Thermo 250
Material	Stainless Steel
Power source type	Corded Electric
Voltage	120 Volts
Wattage	165 watts
Item Package Quantity	1
Flow Rate	250 Gallons Per Minute
Maximum Pressure	8 Bars
Plug Profile	Wall
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
Specific uses	Indoor
Included components	Aquarium Filter with heater, filter media, tubing, intake and outflow tubes, diffuser, spray bar, fittings, and power cable
Batteries Included?	No
Batteries Required?	No

Common Questions

Are the products genuine and authentic?+

Yes, all products are sourced directly from authorized retailers in the US, UK, UAE and India. We maintain strict quality control processes and verify each product before shipping. All items come with applicable manufacturer warranties and are covered by our standard return policy.

How long does delivery take and is it reliable?+

Delivery times vary by destination country, typically ranging from 3-9 business days. Each order is fully trackable through our system. We handle all customs clearance and use reliable courier partners for last-mile delivery. You'll receive regular updates about your order status via email and our app.

What is Desertcart? Is it safe to order from?+

Desertcart is an international e-commerce platform operating since 2014. We securely process thousands of orders globally each day. Every product goes through our quality verification process before delivery, and we provide end-to-end order tracking, 24/7 customer support, and a comprehensive returns policy to ensure a safe shopping experience.

How is product pricing calculated?+

Our prices include the product cost, international shipping, import duties, customs clearance, and local delivery charges. We handle all customs and import procedures, ensuring there are no hidden fees upon delivery. PRO members receive additional benefits including free shipping.