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OASE

OASE BioMaster External Filter for Aquariums Up to 90 Gallons, Multi-Stage Filtration, Easy Maintenance Prefilter, Quiet Canister Filter, German Engineering

  • Based on 88 reviews
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Style: Biomaster 350


Features

  • THE MOST CONVENIENT CANISTER FILTER ON THE MARKET The BioMaster's EasyClean Pre-filter module can be removed separately from the rest of the filter. This makes maintenance fast and simple. It also increases filter efficiency and extends the life of main filter foams.
  • ADD A HEATER - Easily integrate an OASE HeatUp heater into the BioMaster filter. Adding the heater to your canister minimizes the amount of in-tank equipment, while also protecting inhabitants from direct contact.
  • CLEAN, CLEAR, HEALTHY WATER Engineered with 4-stage sealed filtration pathways, this filter ensures water travels the most efficient path through activated carbon foams, filter foams of differing pore densities, and Hel-X Biomedia all providing ideal surface area for beneficial bacteria settlement.
  • BUILT-IN SAFETY FEATURES - Designed with safety locks on the handle, pre-filter, and aquastop to avoid spills during maintenance. The aquastop is detachable for easy movement of the filter without affecting the tubing setup.
  • QUALITY DESIGN Made in Italy, with German engineering from OASE and backed by a 4-year warranty (3 + 1 year with online registration). Includes all the necessary fittings for your setup: intake tube with inlet strainer, water distributor nozzle, spray bar, inlet adapter and outlet adapter with flow control, tubing, fittings, heater adapter, and 6 ft. power cord.

Description

"The OASE BioMaster Filter is a game-changer for aquarium enthusiasts, offering convenience and efficiency. Its unique EasyClean Pre-filter module allows you to quickly remove and clean it without having to disassemble the entire unit. This reduces maintenance time and boosts the filter's performance while prolonging the life of the main foams. The best part? Thanks to quicker and simple maintenance, you spend more time enjoying your beautiful aquarium! You also have the option to add a heater to your BioMaster (not included). Adding an OASE HeatUp will help reduce clutter inside the tank, but it also keeps your aquatic inhabitants safe from direct contact with the heater. The BioMaster's four-stage filtration system guarantees crystal clear water, as it flows through various media, including activated carbon and OASE Hel-X Biomedia, creating an ideal habitat for beneficial bacteria. Safety is also a top priority, with secure locks and an aquastop feature that prevents spills during cleaning. Manufactured in Italy with German engineering, this filter quality is unmatched and OASE stands behind the quality of the product with a 4-year warranty (3 + 1 year when you register online). Included in the box are all the necessary accessories for your set-up, so you'll be up and running so you can enjoy your aquarium!"

Brand: OASE


Tank Volume: 90 gallons


Special Feature: Created for installation under the aquarium, Fresh and marine water compatible, Includes a self-priming function for simple startup and continued operation See more


Product Dimensions: 9.4"L x 9.4"W x 9.4"H


Item Weight: 12.3 pounds


Specific Uses For Product: Indoor


Style: Biomaster 350


Color: Black


Included Components: Aquarium Filter with filter media, tubing, intake and outflow tubes, diffuser, spray bar, fittings, and power cable See more


UPC:


Product Dimensions ‏ : ‎ 9.4 x 9.4 x 16.7 inches; 12.3 pounds


Manufacturer recommended age ‏ : ‎ 1 month and up


Item model number ‏ : ‎ 55146


Date First Available ‏ : ‎ May 31, 2018


Manufacturer ‏ : ‎ OASE


Best Sellers Rank: #158,476 in Pet Supplies (See Top 100 in Pet Supplies) #2,680 in Aquarium Filter Accessories


#2,680 in Aquarium Filter Accessories:


Customer Reviews: 4.4 4.4 out of 5 stars (88)


Brand Name: OASE


Included Components: Aquarium Filter with filter media, tubing, intake and outflow tubes, diffuser, spray bar, fittings, and power cable


Model Number: 55146


UPC: 706759551465


Number of Items: 1


Global Trade Identification Number: 65


Manufacturer: OASE


Unit Count: 1 Count


Item Type Name: Filter


Manufacturer Part Number: 55146


Warranty Description: 3 year limited + 1 year warranty extension with online registration


Additional Features: Created for installation under the aquarium, Fresh and marine water compatible, Includes a self-priming function for simple startup and continued operation


Specific Uses For Product: Indoor


Vivarium Type: Aquarium


Pet Type: Fish


Target Species: Fish


Tank Volume: 90 gallons


Item Dimensions L x W x H: 9.4"L x 9.4"W x 9.4"H


Item Weight: 12.3 pounds


Product Style: Biomaster 350


Color: Black


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Wednesday, Oct 14

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Similar Products

Top Amazon Reviews

    • Air Purging is a big issue but can be corrected changed to yes you can!
Style: Biomaster 350
Review Image by Proudvet
7/21/23 First I want to say that all three Oase Biomaster filters ,I paid for with my own money. They were not given to me to write a review. I have been running filter now with modified in canister prefilter setup and this mod is doing exactly what it is supposed to do as far as acting as a prefilter . Was a little concerned at first that their would be a bypass with the removal of prefilter pipe but that has been dispelled with inspection . As far as ANY air purge it is NON-existent .To any one who has this filter I would strongly suggest doing this mod. All it will cost is the price of two Tetra pond prefilter sponges approximately $5.50. I am going to try to add a picture of 55 gallon this filter is running on . Notice Sword plants to the left and see the flow coming out which was not there before. And yes I am running Co2 with an inline Co2 Art diffuser on Oase. Something that questionable customer service people at Oase said would cause purging . The bubble count is about 5 per second ,no fooling around injection quantity. 5/19/23 Yesterday cleaned Biomaster 600 . Now that I have totally identified the cause of purging air from this filter I decided to try another Mod. I took another Tetra Pond pre filter and stuffed it into the empty prefilter housing . Made sure to keep it at the top of the housing so it is essentially up against the primer housing to avoid bypass. Of course left out prefilter pipe . The coarseness of the internal Tetra sponge coupled with the elimination of the pipe has made this canister SOOOO far a great filter. No purging ,no flow problems and I'm back to an easy clean internal prefilter. Regardless what happens with this latest mod I still have No purging and an improved flow rate . Tetra Pond sponge is still on in tank pickup tube . Think I will change rating to 5 stars. Again this is on a heavily planted overstocked 55 gallon that I rarely do water changes on . No amonia,no nitrites and Nitrates are down around 15ppm to 20ppm even with addition of ferts. 4/18/23 Just want to let anyone looking at this that purging is GONE . In canister prefilter and pipe removal made all the difference in the world . Also drop checker for CO2 is looking better (more towards a lighter green color) without Oase doing it's air injection. Another Update 4/11/23 I will start with the positive and try not to mention the Oase corporate line on their canisters problems . One very telling thing in this whole Oase journey for me is the fact that owning the Biomaster 250 along with the 350 and the 600 showed me that Oase should have stopped at the 250. I am running that filter with a very fine sponge on the intake in the tank . It is solidly clogged with muck and it DOES NOT purge air at all . The pre filter in the filter housing is never dirty due to what is on the in tank pick up. Just recently picked up 3/4 inch pvc pipe Reemed out one end to fit on primer head ,drilled the living crap out of pipe (almost to point of breaking ) . Installed coarsest pre filter sponges on (swiss cheese looking pipe) and installed in 600 canister . Not any noticeable difference in performance ,flow wise and definitely did not help purge issue . I do have on 600 tank intake tube a VERY coarse Tetra Pond pre filter . What happens like the 250 the oase 600 canister pre filter never gets dirty . But still has the Purge issue . SOOO what I have done was removed every thing from the canister pre filter(wasn't doing anything anyhow ) and it improved flow also I could be wrong but it helped so far with purging . If I am correct maybe and I am saying MAYBE two problems have been cured .Reason for statement on flow is because I have a very heavily planted tank and plants are leaning over from current that never did before . No scientific gallon per hour check just and unscientific observation. I will definitely stay with Tetra Pond Filter prefilte arrangement as long as I am using this filter. https://www.amazon.com/gp/product/B002RBEGC8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Update 1/17/23 Well after extensive conversations by phone ,Email and Text with Adam Raab who has the title of "Aquatics Category Manager (North America) / Regional Sales " The answer to the well known air purging issue with these way over priced filters is to send them back to where you purchased it from . Apparently it looks like they either don't know how to fix them or they don't care to. So here it is ,if you inject CO2 in your tank you definitely DO NOT want this filter ,or if you like spending money to get your co2 refilled a lot more frequently because your Oase combo canister filter /air stone carried the co2 you just injected up out of your tank then this is the filter for you. Yes folks Oase has answered the question of where to put the air stone in your tank, its all incorporated into the return from your wonderful Oase all in one filter and oxygen delivery device. I can't understand where the positive reviews are coming from . It cannot be from customer service because when you speak to anyone from the company all you get like their filter is a lot of air unlike the filter theirs is hot. I have been in the tropical fish hobby since I was in my early teens . I am now 73 and I think I know a little something about keeping fish and equipment that goes with it . Unfortunately In 2019 I made the mistake of buying this joke of a canister filter the Biomaster 350. From day one it constantly purged air,early on that is to be expected ,but this thing never stopped. I tried a few things as far as the way the media is in the filter and that never made a difference . With all the air purging into the tank water looks like Sprite. I even went with a courser inside canister pre filter thinking that may be issue . No it was not . A couple of years ago when I called Oase about problem their answer was to send me a new head unit , cured nothing. They did admit that they had issue back then and that was reason for exchange head. I have to clean pre filter every two weeks which helps slightly . I just got off phone with Oase and now they say they don't have problem with 350's and when I asked why they sent me exchange head unit a couple years ago and admitted to issue then ,now they have no answer . All Oase is admitting to is the problem is with the 600 which is the exact same filter as the 350 except a little bigger otherwise identical. Before you go and spend good money on this do a lot of investigating ,Oh did I mention the flow out of this so called filter also sucks . Save your money and stay way from Oase. Looks like I am going back to Eheim canister I bought back in 1977 ,never again Oase. Probably if I said my problem was with a 600 they would have admitted to 350 being the problem. I think what Oase is proficient in is the art of Flimflam . Update 8/4/22 : If you have this filter get yourself a jar of silicone grease and silicone all of the gasket areas on this filter. Not just a like film of silicon but I'm talking about slopping this stuff on . I tried a light film ,did not work . Then I bought silicone grease in jar and went crazy with it at every gasket and joining parts this filter has,knock wood problem with air for the most part is gone. Still have a little purging but that is to be expected especially as filter gets dirty . From Amazon : Food Grade Food Grade Pure Silicone Grease, 2.0 fl. oz. (59 ml) Jar Update 10/5/2022 I have updated my rating because of one thing I have recently found out and had an Oase rep admit to it . If you use a foam prefilter on your in tank intake or in the case of a planted tank where there is some dead plant material on intake you will cause more and heavier air purging from filter. What is happening is the pump is causing cavitation inside the filter because of restriction at the intake . I haven't tried a very coarse foam pre filter but I have noticed that slightest restriction at in tank intake will cause increase in purging of air. My tank is very heavily planted and i have noticed it more often .Essentially the filter works well and is well built and that is reason for change in rating . Unless Oase gets a new arrangement for intake I would not use it on a tank with shrimp and such. ... show more
Reviewed in the United States on March 18, 2022 by Proudvet
    • OASE BioMaster 600 Canister Filter – My Experience So Far
Style: Biomaster 600
Review Image by Ray C.
I received the OASE BioMaster 600 a few weeks ago and have been running it on my 55-gallon planted tank since. I’ve used a few different canisters in the past (including Fluval and Marineland models), and this one easily stands out in terms of build quality and thoughtful design. Setup & Installation: Unboxing was straightforward, and everything arrived well-packed. The included media trays were preloaded, which saved time, and the filter came with an adapter for adding an inline heater — a huge plus if you want to keep equipment out of the tank. Installation took under an hour. The Quick Release prefilter module is clever and genuinely helpful for maintenance. Hoses are a bit stiff out of the box, but they relaxed with some warm water. Performance: Running this on a moderately stocked tank with CO₂ injection and high plant load, the flow rate has been consistent, and water clarity is excellent. The integrated prefilter does a solid job catching debris before it reaches the biomedia, and it only takes a few minutes to pop it out and rinse. Compared to my previous Fluval 407, the OASE runs noticeably quieter — a soft hum that’s barely audible under the stand. Build & Design: Feels sturdy and well-engineered. The primer is one of the best I’ve used — took about three pushes to get it going. The tray system is intuitive and seals well, with no leaks or bypass issues. I also appreciate that it doesn’t take up a lot of space in the tank itself; everything’s external, and the footprint under my stand is compact considering the capacity. Pros: Excellent build quality and modular design Quiet operation Easy-to-access prefilter reduces full cleanings Heater integration option Strong, consistent flow even with media fully loaded Cons: Hoses are rigid and take time to adjust A bit pricey, especially if you're not planning to use the heater module Overall: This filter feels like a long-term investment, especially for high-tech or heavily planted tanks. Maintenance is easier than most, and the performance has been reliable so far. If you're willing to spend a bit more for convenience and quiet, it's worth every dollar. I’ll update if anything changes over time, but so far it’s been a rock-solid addition to my setup. ... show more
Reviewed in the United States on June 8, 2025 by Ray C.
    • Easy Flow, Easy Clean
Style: Biomaster 850
I love the preFilter option and the inline heating. Dont have to do deep filter cleaning as often. They are a little noisy at first but after a couple months or even less they break in and get A LOT quieter. The out flow isnt as strong as on some other filters in this price range, so if you need a stronger outflow this wouldn't be the one for you. But, if your fish need a calmer water its perfect! ... show more
Reviewed in the United States on December 15, 2025 by Pamela

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