---
product_id: 97759215
title: "OASE Indoor Aquatics Biomaster Thermo 350"
brand: "oase"
price: "€ 749.27"
currency: EUR
in_stock: true
reviews_count: 8
category: "Oase"
url: https://www.desertcart.fi/products/97759215-oase-indoor-aquatics-biomaster-thermo-350
store_origin: FI
region: Finland
---

# 4-stage advanced filtration system Whisper-quiet external filter Integrated heater for precise warmth OASE Indoor Aquatics Biomaster Thermo 350

**Brand:** oase
**Price:** € 749.27
**Availability:** ✅ In Stock

## Summary

> 🔥 Elevate your aquarium game with flawless warmth and clarity!

## Quick Answers

- **What is this?** OASE Indoor Aquatics Biomaster Thermo 350 by oase
- **How much does it cost?** € 749.27 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.fi](https://www.desertcart.fi/products/97759215-oase-indoor-aquatics-biomaster-thermo-350)

## 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

- • **Whisper-Quiet Operation:** External filter runs silently, maintaining tranquility in your living or workspace.
- • **Quadruple Filtration Power:** Biological, mechanical, chemical, and prefiltration stages guarantee pristine, healthy water.
- • **Crystal Clear Views, Zero Clutter:** Compact filter design keeps your aquarium visually stunning and unobstructed.
- • **Seamless Aquarium Climate Control:** Integrated heater ensures consistent, uniform temperature for optimal aquatic life comfort.
- • **Effortless Maintenance & Performance:** All-in-one design simplifies upkeep while maximizing water quality and fish vitality.

## Overview

The OASE Indoor Aquatics Biomaster Thermo 350 combines a compact external filter with an integrated heater, delivering precise temperature control and whisper-quiet operation. Featuring a comprehensive 4-stage filtration system—biological, mechanical, chemical, and prefiltration—it ensures crystal-clear, healthy water while maintaining an unobstructed aquarium view.

## Description

OASE Indoor Aquatics Biomaster Thermo 350

Review: Great aquarium filter! - 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.
Review: Best Canister Filter Ever! - 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.

## Features

- The Bio master thermos 350 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

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B07M59ZGKX |
| ASIN  | B07M59ZGKX |
| Age Range Description | All Life Stages |
| Best Sellers Rank | #107,009 in Pet Supplies ( See Top 100 in Pet Supplies ) #1,843 in Aquarium Filter Accessories |
| Brand | OASE |
| Brand Name | OASE |
| Color | Black |
| Country of Origin | Italy |
| Customer Reviews | 4.2 4.2 out of 5 stars (784) |
| Date First Available | December 19, 2018 |
| Date First Available  | December 19, 2018 |
| Directions | See Packaging |
| Efficiency | High |
| Global Trade Identification Number | 00706759551496 |
| Is Discontinued By Manufacturer  | No |
| Is Electric | Yes |
| Item Depth | 16.7 inches |
| Item Dimensions LxWxH | 9.4 x 9.4 x 16.7 inches |
| Item Package Dimensions L x W x H | 18.1 x 14.4 x 11.4 inches |
| Item Weight | 12.35 pounds |
| Item model number | 55149 |
| Item model number  | 55149 |
| Manufacturer | OASE |
| Manufacturer  | OASE |
| Manufacturer recommended age  | 1 month and up |
| Maximum Flow Rate | 1100 Liters Per Hour |
| Model Name | OASE Indoor Aquatics Biomaster Thermo 350 |
| Mounting Type | None/Not Applicable |
| Number of Items | 1 |
| Product Dimensions | 9.4"W x 16.7"H |
| Product Dimensions  | 9.4 x 9.4 x 16.7 inches; 12.35 Pounds |
| Size | 16 W / 9.4 IN |
| 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 |
| Specific Uses for Product | Indoor |
| Style | Biomaster Thermo 350 |
| Target Audience Keyword | Fish, fish |
| UPC | 706759551496 |
| Voltage | 120 Volts |
| Warranty Description | 3 year limited + 1 year warranty extension with online registration |
| Wattage | 216 watts |

## Product Details

- **Brand:** OASE
- **Capacity:** 350 Liters
- **Power Source:** Corded Electric
- **Product Dimensions:** 9.4"W x 16.7"H

## Images

![OASE Indoor Aquatics Biomaster Thermo 350 - Image 1](https://m.media-amazon.com/images/I/71dvHb0YPmL.jpg)
![OASE Indoor Aquatics Biomaster Thermo 350 - Image 2](https://m.media-amazon.com/images/I/61JAzlq1FCL.jpg)
![OASE Indoor Aquatics Biomaster Thermo 350 - Image 3](https://m.media-amazon.com/images/I/71GhvYmH9yL.jpg)
![OASE Indoor Aquatics Biomaster Thermo 350 - Image 4](https://m.media-amazon.com/images/I/81iV5-raLqL.jpg)
![OASE Indoor Aquatics Biomaster Thermo 350 - Image 5](https://m.media-amazon.com/images/I/71VA0JixhvL.jpg)

## Available Options

This product comes in different **Style** options.

## 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 November 21, 2025*

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.

### ⭐⭐⭐⭐⭐ Best Canister Filter Ever!
*by S***. on January 29, 2020*

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.

### ⭐⭐⭐⭐⭐ Great for Saltwater Reef Tank
*by M***E on October 19, 2024*

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!

## Frequently Bought Together

- OASE Indoor Aquatics Biomaster Thermo 350
- Seachem Matrix, 4 L / 1 gal.
- FZONE Aquatic Glass Lily Pipe Set with Skimmer Inflow and Outflow for Aquarium Filter 5/8''(16/22mm) Tubing

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*Product available on Desertcart Finland*
*Store origin: FI*
*Last updated: 2026-02-20*