OASE BioMaster External Filter for Aquariums Up to 160 Gallons, Multi-Stage Filtration, Easy Maintenance Prefilter, Quiet Canister Filter, German Engineering

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.

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.

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!

Revised review after 1.5 years use. Contrary to what seems to be popular belief, these filters are great at removing air if you just leave it alone while it does so. Tipping the filter will result in leaks. Long runs of tubing destroys flow rate, cut the tubing as short as possible. Clean or replace prefilter every 2 or 3 days, clean the inside of the tubing every other week (you will be amazed at the difference this will make to both flow rate and fish comfort), clean the cannister every other week and rinse the media in tank water each cannister cleaning. Using a drill, double the number of holes in the prefilter tube, use 65ppi prefilter sponges and "lock" them into place using one of the plastic clips supplied for the spraybars - if you don't lock them, they will slide down during use and allow detritus to bypass the prefilter directly into the filter bed. Block the flapper at the bottom of the prefilter container by cutting a filter sponge to fit the opening and lock it in with the flapper to prevent the flapper from moving (this may make it difficult to use the primer device - I don't use it anyway) - failure to do so will result in detritus flowing out of the prefilter container directly into the filter bed and result in a buildup of yuck around the base. Anything allowed to bypass the prefilter will shorten the life and effectiveness of your bio media. Also, make sure the top of the prefilter (with the blue bulb on it) fits correctly into the prefilter container or once again detritus will bypass the prefilter through the openings where they are supposed to lock together - it is necessary to replace the top part occasionally as the tabs that lock into the bottom container go bad after a while. Bottom media basket you want to cut to fit sponge filter pads with medium on the bottom and fine on the top, the rest of the baskets should be filled with a sintered glass bio media. Don't waste your time with the carbon impregnated sponges, use the top half basket for carbon inside a fine media bag. Throw away the useless blue and orange sponges that come with unit. original review: I have both the 600 and 350, and they both do a great job. Overall the filtration is great and my aquarium water hasn't looked so good since before I installed these. Each basket will hold 1 liter of sintered glass bio media and the fine pre-filters do a good job of keeping the bio media clean. There are a couple of negatives too though. First, unless you first lock and remove the inlet/outlet tubing there is no way you can remove the pre-filter without spilling water because of the back pressure - something that is problematic in that I change out pre-filter cartridges daily (I have spares for each). About 25% of the time that I swap out the pre-filter on the 600 removing the tubes will result in a leak because I have to move the filter with the tubes disconnected to remove the pre-filter cartridge. Also, the filters are louder than I would like - not terrible, but louder than previous canister filters I've had. Having said all that, I'd recommend the Biomaster filters based on the massive amount of biomedia they hold, and their overall performance in keeping the tank clean and the fish happy.

I bought my first Oase Biomaster 350 for my overcrowded 60 gallon N. Brichardi tank to replace a SunSun that sounded like haybailer I could hear on the other side of the house. The Biomaster had many reviews touting how quiet it was, so I was a buyer. Later, I started a 29 gallon planted tank so of course I went with another Oase Biomaster 350 Thermal this time. When the other SunSun type filter crapped out on the 60 gallon I went with the Biomaster 600. I’ve never been happier with my purchases. I have NO problems with purging or bubbling. The 600 will gas off for maybe ½ an hour after a pre filter cleaning…the two 350’s never purge. All of them just sit there and quietly do their job. I believe that the purging that some others complain about are either operating error such as not getting tight connections on the hoses, not running a coat of Vaseline or silicone grease on the tank o-ring…or a warranty issue (warped lid or bad o-ring IDK?)that Oase should take care of. I also believe aquarist who listen to that foolish Irishman hacking over priced clay or any of the other snake oil biological filters on the market produced to filter the money from your pocket. I am a firm believer that the 30 or 40 ppi sponge that come with the Oase filters is the ultimate biological filter medium. The sponge allows the oxygenated water to flow throughout thus supporting huge amounts of beautiful brown biological mass. Save your money and set the filter up just the way it comes from the factory. The only “pimp” I do to my filters is drill in more holes in the pre-filter tube. I use the fine black Oase pre-filters but have added the big ugly Eheim pre-filters on the intake tubes. The Eheim filters are pretty coarse and do a great job of collecting the big nasty stuff. I clean those out about one every 7 to 10 days and only need to clean the fine Oase pre-filter about once a month. I only crack open the main filters maybe once a year (usually not necessary even that often) for a light swish around in a bucket of tank water and back to work. The biological filtration is beyond belief. Water tests show no ammonia, nitrites, or nitrates. I could really use more nitrates to help the plants but no complaints about that. I’ve had many different aquariums since 1971, running every type of filter from under gravel and the old Metaframe hang on back to now what I consider the ultimate; Oase Biomaster.

I’m pretty happy with this canister filter so far. It’s very quiet, easy to set up and prime. Mine came with the better pre-filter tube. It’s easy to clean the pre-filter, but from what I see online, it has to be cleaned more often (every one or two weeks) especially if you’re overstocked and have a lot of plants. The good thing is, the rest of the filter stays very clean and doesn’t have to be cleaned for all really long time. I purchased the heater separately to get a cleaner look in my tank. This replaced an older canister that I over tightened and broke one of the plastic screws on. I may stay with this brand if all goes well long term.

I'm using this 250 on an all in one converted reef tank that now is a planted shrimp tank. Here are some observations: 1. Well made, great design and quiet (except for the annoying air bubbles, purging that happens with regularity. Not sure what I can do about the air bubbles as it probably is a design flaw that wont go away.) 2. Instruction inefficient. Thank God for YouTube or I would have returned it as a damaged unit even though it is not. The open and close toggle arm to remove the chamber will not allow you to turn it to the open position unless the other one where you add your intake and out hoses is already in the open position, so do not attempt to turn it or you could break it. I almost did. 3. Love the simplicity of cleaning it! That first chamber is what traps most of the debris and can so easily be taken out and cleaned weekly! Awesome. 4. If power goes out you dont have to worry about this thing needing a prime, works right away and is very quiet and small factor. 5. This (American) model doesnt allow you to put a heater it in, I personally dont care but just an fyi. 6. Air bubbles... If you hate purging of air and air bubbles dont buy Overall I like this thing. I DONT feel badly giving it 2 out of 5 stars BUT I do NOT at all regret the purchase and it has made my water crystal clear but it has some annoying issues that I have no solution for yet. You will not be disappointed with the 250. I use it on my 26 gallon and it is adjustable but I feel it's perfect for my betta shrimp setup. Wish air bubbles were not so prominent. Update 3/20/20: the noise from trapped air inside the container is still there but not as bad. Also the water is crystal clear. Love this thing but it scares my cats with the weird noises... Update 9/22/20: Well I have a much cheaper hang on the back filter coming today from Amazon. This OASE proved to be a huge waste of money. Unfortunately the pump stopped working efficiently and could not pull/push water at all. I took it the top apart cleaned everything multiple times changed the intake and outtake lines shortened them etc etc. luckily Amazon is quick to ship out replacements or my fish might be suffering from this weak piece of equipment. I went to the oase site to try and find a replacement pump with no success.

I've had this filter for a few years. Zero problems - unlike my old Fluval 405. The Oase is quiet, easy to clean the pre-filter, and generally easy to service. Keeps the water crystal clear in my 70 gallon freshwater (along with a Biowheel Emperor 400).

Excelente filtro, ya voy para 2 años xon el y es genial, me parece muy buena opcion uanque recomendaria adquirir la version 2 que sacaron que esta mejorado

El filtro es muy bueno pero lo devolvi por ruidoso y no me han devuelto el dinero después de 9 dias

Comme le titre le dit ce filtres est la Cadillac des filtres avec sont prefiltre qui nous aide énormément au lavage des filtres sans être obligé d'ouvrir le canister la ya rien de mieux pour vrai et pour ça grosseur il est très silencieux

This was so easy to setup even for a first timer like me. It operates completely silent which is a large bonus. Easy to clean, straightforward to operate and keeps my 90 gallon tank water pristine.

I really like this filter. It's big. It's almost silent and has a built in heater. It's a bit louder than my Eheim Pro 4 which is too bad otherwise it'd get 5 stars. When the cabinet's closed the Eheim Pro 4 is 31 decibles at three feet. The Oase BioMaster Thermo 850 is 33-35 after a month of letting it burn in. I thought about doing alot to sound proof my cabinet but ended up feeling I'll get used to the other 2-4 decibels and I probably will. The wife doesn't mind at all. Only other complaint is that it tends to burp water when you disconnect the tubing which isn't desirable getting it inside your cabinet but not a biggie and something you can plan for. Otherwise great, and lots of room for your media and filtration (get rid of the stuff they give you it's garbage).