OASE BioMaster Thermo External Filter with Built-in Heater for Aquariums up to 90 gallons, Multi-stage Filtration, Easy Maintenance Prefilter, Quiet Canister Filter, German Engineering

This is my first external canister-type aquarium filter and I'm very happy with my purchase. Going from a 10 gallon tank with various hanging filters (Tetra, Fluval, Marineland) to a larger (50? gallon) tank with a red-eared slider was a big difference for me. Turtles are very very messy, so I knew I had to make the change when putting him into a bigger tank. I was nervous at first but now that I've had this for several months, I am comfortable with disassembly for routine cleaning. About 3 months into use, it started getting louder and louder. After ruling out air in the lines, I figured it had to be the impeller, but getting to it requires removing a housing that was impossible for me. Cleaning the impeller is part of routine maintenance so I knew it was not only possible but necessary- I just couldn't get to it. My hubby had to use the provided tool along with a little man-handling. Now that it's been removed once, I am able to to do it myself from now on, but it was just that first-time I couldn't untighten its cover. Again, I'm very happy with my purchase as it is quite easy to clean (now that my husband has loosened all the fittings) and it keeps the water super clear. It doesn't leak, is completely silent (when maintained properly), and is pretty straightforward to setup and maintain. The only criticism I have is that there's no indicator for the heater - there's no light that it's on and working, and even if there was a light you wouldn't be able to see it since it's internal. So your only indication of a burned out heater would be cold water. This hasn't happened yet but is something I think about.

I LOVE IT! I've been using two of these Thermo 250's on my freshwater 55 gal, for 3 weeks+ now. The Thermo 250 cost a lil more than most canister filters, but has 2 great features that make it worth the extra price. 1: It comes with a built in heater which is great, because that's less clutter in your aquarium. 2: It has a pre-filter on the intake that can be pulled out and cleaned separately, so you don't have to always clean the whole canister, and you can keep that good bacteria growing in the main filter trays. 3: It comes with 4 trays to add media too. 4: It's super quiet, my 60 gal rated air pump is louder then both of my 250Ts combined, and the air pump really quiet. I have not had to do any maintenance in my first month of running and the water flow is still very strong in my heavily fish stocked/planted aquarium. I have to be honest though; I'm only using the coarse circular intake filter pads that came with it, because I upgraded just about everything else. I also added jardli glass water intake and glass water outtake for that kool less clutter look. This is because I did some serious research on the net and good ol youtube. After a long search on all types of aquarium filters ie.. hang on back, canister, sponge, under gravel and sup, I came across this Thermo 250 Canister from Oase. Now just about all if not every youtube video on it was from a none english speaking country. Then I seen this random video that said "pimpmyfilter". I clicked on it and some British guy named the "pondguru" was giving a demonstration on how to make the Thermo 600 model more efficient. After watching that video I was completely hooked/sold on his way of making the Thermo Canister filter more efficient. I didn't do the drilling though, cause it doesn't seem to be needed, the water flow is still very strong. With that being said I can't give an honest opinion on how good the filter media is that came with it like the meduim and fine pads and the ceramic balls. Because, I pimped out both of my Thermo 250s from start. I am using the original black fine pads for the prefilter, because they work the best for trapping muck and not letting it through to the main filter. No matter what type of filter you get whether it's this one or another model or brand, I highly highly recommend that you go on YouTube and type "pimpmy(filter name here)filter" ie pimpmyoasethermofilter, pimpmyfluvalfilter, pimpmywhateverfilter. I promise you that that will be the most helpful thing you ever did when it comes to searching for and aquarium filter. No-one on the internet that I've seen is doing anything remotely close to what that guy does to aquarium fliters. He didn't pay me or ask me to promote his channel. He'll probably never know that I'm promoting his work. I'm just giving him mad props because he deserves it. Watch and see, and I bet you'll come back looking for this review to say that it really helped you.

I purchased this OASE BioMaster Thermo 350 canister filter on Amazon Prime about a month ago for use with my new 32-gallon fresh water planted aquarium. This canister filter is beautifully designed and engineered in Germany, and built in Italy. This is a VERY high-quality piece of aquarium equipment with several excellent built-in features. I’ve owned aquariums for over 40 years and this is hands-down the BEST canister filter I’ve owned. The pump primer feature is powerful and effective, easy to use, and gets the filter up and operating almost immediately after applying power. The ability to shutoff and remove the 5/8” ID inlet and outlet hoses without spilling any water is an EXCELLENT FEATURE, as is the ability to remove and clean only the pre-filter. The stacking media trays are VERY easy to remove and clean, and allow the use of several different types of filter media. This unit was clearly designed by people familiar with aquarium equipment for people who use aquarium equipment! The built-in heater works great and keeps my aquarium rock-steady at the selected temperature. The pump motor is almost silent with virtually NO irritating vibration. The 5/8” ID hose supplied with the unit is tinted to hide algae and of excellent quality. I give this OASE BioMaster Thermo 350 canister filter my strongest recommendation. While not inexpensive, it works beautifully and is well worth the cost. Please see my photos.

Let's get the negative out of the way first. When I received this, one of the rubber gaskets internally was torn, so I emailed Oase support with photos asking for a replacement gasket as I didn't want to return the entire product and hold up my aquarium build. I received the automatic confirmation email back, but never received an reply. After 2 weeks, I emailed again. They then promptly replied and said that the gasket was on back order and would not be available for another 4 months. They suggested I return it and get a new filter. I looked at it and didn't think it would cause any leakage, but thought it may lower the throughput of the filter. I chose to go with it and replace it at a later time at my own expense. Hopefully they won't make me purchase a new pre-filter assembly. The filter is working just fine. This made it a 4 star. If the gasket was good, I 100% would have given 5 stars... The only other thing I don't really like about the filter is the intake/output design. There are a few other cannister manufacturers out there that make the transition from hose to tank a bit nicer. The squarish fittings over the top of the tank are kind of floppy, only to have 1 suction cup on the output and 2 suction cups on the intake barely helping to hold it in place. This is compounded by the fairly stiff hose makes for a bit of a twisting bending moving activity to get everything to sit right on the tank. Don't get me wrong, it works, but I'm just saying it could be designed a little better. Now for the good. I pretty much like everything about the cannister. The pre-filter and ease of access. The integrated heater. The build quality and design. I did cut up one of the blue coarse filters to use on the pre-filter instead of using the finer sponge that came with it, but that's personal preference. Internally, I used the coarse filter on the bottom (1st media. Flow is bottom to top in the main part of the filter) the fine filter at the top and biomedia between them. Overall, I am extremely happy with this purchase and unless something catastrophic occurs, I will probably be using these exclusively in the future. I whole heartedly recommend this filter.

One of the coolest things ive bought for my freshwater planted tank. The Oase Biomaster 350 is a beast and a QUIET one at that, I have powerheads louder than this thing and I have to touch it to see if its on. The only thing I was disappointed with was that only one bag of bio media is included, the rest are sponges - so I added Seachem Matrix to two of the other trays along with the included biomedia. If youre feeling fancy you can opt for the Aquario Neo Lily pipes size large but the stock pipes are fine, just not as fancy. Water flow is good, a little more mellow than I expected with the spray bar, build quality is exceptional, easy to setup and go and the self siphoning feature is gold. Great price right now too, I have the UNS Delta 90 and it was cheaper than the Oase but the Biomaster is almost twice the capacity and quieter. Wish I'd gone Oase all the way.

Got this to replace a leaking penn plax cascade, all media I added to the filter was cycled and had a precycled backup filter on the tank to help everything adjust to the new filter. The tank is 55 gallon shell dweller tank, so tiny fish in a large tank, not overstocked at all. Filter was working great up until a few days ago. Checked everything, hoses, basket the filter itself. Nothing was blocked and everything was flowing nicely. Turned the system back on and realized the 350 GPH it was supposed to be flowing at was down to a mere trickle. We are talking about maybe 10 gallons an hour, at the very least a 4th if not less then the advertised speed. As I had taken everything apart to check I reaffirmed nothing was clogged. It put everything together and contacted Oase hoping they could help me and a slow filter was probably doing some good. Well no, apparently letting it run created a dead spot somewhere in the filter itself. Opened it again and it was reeking of raw sewage. Guess what ammonia spike.... I tore the thing off my tank and am now in tirage mode. Fish are stressed but hopefully, the worse is over. This filter is an overpriced POS. I'd rather trust my fish to a sun sun now instead of this. After trying to contact their customer support, I got the run around for two days. They don't know anything about fish keeping and kept having to go back to talk to the 'one guy that knows stuff' I talked to them on and off and only after 2 days of talking with them did they actually send me the form to get a replacement. I told them I needed a replacement since the beginning of the conversation. But nope! They offered a replacement to be shipped by mail that would take 7-8 business days. Leaving my tank without filtration for 10 whole days. Yeah thanks Oase. Guess you don't know how filters work, kind of need them to keep the tank running.

The Oase Thermo Biomaster 250 canister filter has truly impressed me with its performance and features. Here are the key points I found noteworthy: Design and Build Quality: The filter is well-constructed, featuring a sturdy design that feels durable. The compact size makes it easy to fit in tight spaces, especially in my cabinet. The integrated heater is a game-changer, eliminating the need for an additional heater in the aquarium. Ease of Installation: Setting up the Thermo Biomaster was straightforward. The user manual was clear, and all necessary parts were included. The quick-release valves make it easy to detach the filter for maintenance without creating a mess. Performance: This filter provides excellent water clarity and quality. The three-stage filtration system (mechanical, biological, and chemical) works effectively to keep my tank pristine. The adjustable flow rate allows for customization based on the needs of my aquarium, which is a nice touch. Though I keep the flow rate fully open. Heater Integration: Having a built-in heater is incredibly convenient. It maintains stable temperatures, which is essential for aquatic life. The heater is reliable and adjusts quickly to changes, ensuring a comfortable environment. Maintenance: Maintenance is a breeze with the easy-access filter media trays. I appreciate the reminder for maintenance intervals, which helps me stay on top of cleaning without guesswork. Noise Level: I found the noise level to be minimal, especially compared to some other filters I've used. Conclusion: Overall, the Oase Thermo Biomaster 250 is an outstanding canister filter that combines effective filtration with convenient heating. It’s perfect for aquarists looking for a reliable solution for their tanks. I would highly recommend it to anyone looking to enhance their aquarium setup!

This is the greatest aquarium filter ever! I’ve tried other styles and brands. I now own (3) of these. 1) the integrated heater is great and eliminates having it the tank 2) the pre-filter makes routine maintenance a dream to complete 3) the flow rate is fantastic 4) the ability to customize the media trays is a huge plus I run heavy planted and stocked tanks. The OASE filter exceeds my expectations!

This is the second Oase Biomaster thermo filter I have purchased. They are very well made and provide a large media capacity to fill with your choice of media. The internal pre-filter is a fantastic feature - super easy to remove and clean without disrupting the whole filter. Intake and outflow allow for adjustability with the flow to help fine tune your tank. They are extremely quite with no real noticeable noise. The internal heater is another feature that sets this filter apart from the others. I've used many other brands and some of them are great, but none of them have the features the Oase do or are as easy to use.

The pre-filter and the built in heater both make this lightyears ahead of any other canister filter. So easy to maintain, and very quiet, other than the occasional air burp. Only criticism, is that the GPH is measurably lower than the spec indicates. I wouldn't use this for anything bigger than a 90 gallon aquarium despite what the packaging tells you. I didn't knock a star off for this, only because this is something that seems to be true of all filters.

Buen filtro es el segundo que compro, pero el flujo reduce considerablemente, no pretenda mover 4-5 veces el volumen del acuario, fue diseñado para filtración qué debe ser hasta 4 veces el litraje del acuario, considere el más potente mientras le permita el bolsillo pemro también su gasto de luz. Y mas ruido entre mas potente...!!!

Al año dejo de funcionar correctamente. Gotea por la parte de la tapa.

Absolute unit. Currently have the Thermo 600 set up for my 75 Gal and it’s doing an amazing job. Easy to set up, the priming function works like a charm. Integral heater has kept it at a constant 78 degrees at multiple tested spots in the tank. Pre filter is easy to clean and one of the big reasons I got it. The supplied media is a bit lacking. I purchase several boxes of eheim bio and mech media to fill it up as it’s basically just foam and plastic balls that float and are a pain. Kept one foam at the bottom, eheim mech in the second and then three trays of eheim substrat (one level is from my old filter to jump start), top tray is filter floss and a carbon pad for right now (new tank set up). Switched from an Eheim classic and really like the ease of cleaning this filter compared the old green bucket. Really like the built in heater. Makes the tank look much cleaner. The filter is a heavy beast to take out when it’s full of media and water. The handle on top is robust enough though so it shouldn’t be an issue.