--- product_id: 2063017 title: "Tetra Whisper Internal Filter For Aquariums 20 To 40 Gallons, In-Tank Filtration With Air Pump" price: "€ 70.67" currency: EUR in_stock: true reviews_count: 13 url: https://www.desertcart.hr/products/2063017-tetra-whisper-internal-filter-for-aquariums-20-to-40-gallons store_origin: HR region: Croatia --- # 170 GPH filtration power Whisper-quiet operation Easy Bio-Bag cartridge swaps Tetra Whisper Internal Filter For Aquariums 20 To 40 Gallons, In-Tank Filtration With Air Pump **Price:** € 70.67 **Availability:** ✅ In Stock ## Summary > 💧 Keep it clean, keep it quiet — your aquarium’s new best friend. ## Quick Answers - **What is this?** Tetra Whisper Internal Filter For Aquariums 20 To 40 Gallons, In-Tank Filtration With Air Pump - **How much does it cost?** € 70.67 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/2063017-tetra-whisper-internal-filter-for-aquariums-20-to-40-gallons) ## Best For - Customers looking for quality international products ## Why This Product - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Effortless Maintenance:** Large, easy-to-change Bio-Bag cartridges keep upkeep simple and mess-free—because your time is valuable. - • **Universal Compatibility:** Ideal for 20-40 gallon tanks, supporting a wide range of aquatic pets and setups with reliable efficiency. - • **Whisper-Quiet Performance:** Operates silently with soothing waterfall sounds, enhancing your zen workspace or living room vibe. - • **Powerful 3-Stage Filtration:** Filters up to 170 gallons per hour while oxygenating your tank for crystal-clear water. - • **Sleek Internal Mount Design:** Mounts inside your aquarium, allowing flush placement against walls—perfect for minimalist spaces. ## Overview The Tetra Whisper 40i Internal Filter is a compact, submersible filtration system designed for 20-40 gallon aquariums. Combining a quiet air pump with a 3-stage filtration process, it filters up to 170 gallons per hour while oxygenating water. Its internal mounting clip allows tanks to sit flush against walls, and the easy-to-replace Bio-Bag cartridges trap debris and fish waste efficiently. Trusted by hobbyists for decades, it delivers reliable, low-maintenance performance that keeps aquatic environments pristine and peaceful. ## Description The Tetra® Whisper® 40i Internal Filter for aquariums is the ultimate in quiet, convenient 3-stage filtration. This submersible filter mounts on the inside of the aquarium, rather than hanging from the outside, making it possible to place the tank flush against a wall and easily hide with tank décor. The air pump (included) provides bubbles that move water through the filter, efficiently filtering and oxygenating your aquarium. The water flows through Ultra-Activated® carbon, absorbing odors and discoloration, as well as through the dual-sided mesh of the Bio-Bag® Filter, trapping debris and fish waste. Filters up to 170 GPH while oxygenating water. The Tetra Whisper 40i Internal Filter adjusts easily to high or low water levels with a mounting clip. Each unit includes the filter, air pump, 2 feet of airline tubing and one medium Tetra Whisper Bio-Bag Filter cartridge (change monthly – replacement small filter cartridges available). For 20-40 gallon tanks. Since 1951, Tetra has developed the world’s most comprehensive body of fish food knowledge, and fishkeeping enthusiasts have looked to the brand for products and solutions that add ease and beauty to their home. Whether you're an experienced hobbyist or just starting out, Tetra has everything you need – from a large variety of quality fish food and innovative equipment to test kits and decor. Review: Love, Love This Filter! - Okay so... I have a 20 gallon temporarily for my 4 inch turtle. I accidentally bought the smallest of this tetra filter, so I bought the medium sized one in it's place. I had only had the tank filled halfway anyway since my turtle was only 1.5 inches at this point. Mind you I didn't realize how fast they grow, and had no idea that Its recommended to have a filter that can filter 2 to 3x the tank size. So I decided to keep both filters in my tank. One on each side. Even though I still don't reach the recommended filter size, my water now almost filled to the top, stays absolutely clean. Turtles are pretty messy so I still have to do the weekly cleanings and all that extra stuff that apparently those who spend hundreds of dollars on filters still have to do as well. I don't know if this is some kind of luck thing, I don't know if maybe my turtle just isn't that dirty (yea right, I see him)... but I'm actually not looking forward to switching out my filter for the 'recommended' filter size, as these filters work so good. I love them. They are both very quiet. Aside from the sound of the water falling back in.. I mean it sounds like a waterfall. Who doesn't want to hear a waterfall? I love it. This can also be prevented by raising the water level or lowering the filter itself. Basically the closer it is to the water, the quieter it is. Such a simple device, yet so beautifully sufficient. The little one stopped working at one point and I thought... welp there you go! Get what you pay for. But nope! Removed the base, pulled out the magnetic spring propeller and tube, cleaned it out and like magic it started right up as soon as I plugged it back in. Love how easy it is to replace the filters. The filters themselves are great and definitely hold on to some dirtiness. One thing I'll say is there is quite a bit of unused empty space. I now take advantage by adding some extra media, but I must say that these filters work great even without the extra. Love this filter and would recommend above any other filter. Review: 👍🏼 - This fish tank filter has been a solid addition to my aquarium setup. It keeps the water clear and clean, and I’ve noticed a big improvement in overall water quality since using it. It runs consistently without much maintenance and helps maintain a healthy environment for the fish. It’s easy to set up and doesn’t require anything complicated to get started. The flow is steady and helps with circulation without being too strong for the tank. Cleaning it is simple as well, which makes routine maintenance much easier. Overall, it’s a reliable, effective filter that does its job well and helps keep the tank balanced and healthy with minimal effort. ## Features - UNIVERSAL DESIGN: Tetra Whisper 40i Internal Filter is an all-in-one air pump and water filter system. - INTERNAL FILTER: Mounts on the inside of your aquarium with clip (included). - CATCHES DEBRIS: Dense, dual-sided mesh filters debris and fish waste. - AERATES WATER: Air-driven design filters up to 170 GPH while oxygenating water. - CONVENIENT DESIGN: Uses large easy to change Bio-Bag cartridges; filter mounts inside aquarium, making it possible to place tank flush against the wall. ## Technical Specifications | Specification | Value | |---------------|-------| | Customer Reviews | 4.3 out of 5 stars 22,272 Reviews | ## Images ![Tetra Whisper Internal Filter For Aquariums 20 To 40 Gallons, In-Tank Filtration With Air Pump - Image 1](https://m.media-amazon.com/images/I/81W+Z3JdNIL.jpg) ![Tetra Whisper Internal Filter For Aquariums 20 To 40 Gallons, In-Tank Filtration With Air Pump - Image 2](https://m.media-amazon.com/images/I/616wIETjADL.jpg) ![Tetra Whisper Internal Filter For Aquariums 20 To 40 Gallons, In-Tank Filtration With Air Pump - Image 3](https://m.media-amazon.com/images/I/51PTT5eqAQL.jpg) ![Tetra Whisper Internal Filter For Aquariums 20 To 40 Gallons, In-Tank Filtration With Air Pump - Image 4](https://m.media-amazon.com/images/I/41kHtZhL4cL.jpg) ![Tetra Whisper Internal Filter For Aquariums 20 To 40 Gallons, In-Tank Filtration With Air Pump - Image 5](https://m.media-amazon.com/images/I/814us2BTJfL.jpg) ## Available Options This product comes in different **Size** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Love, Love This Filter! *by T***R on September 29, 2023* Okay so... I have a 20 gallon temporarily for my 4 inch turtle. I accidentally bought the smallest of this tetra filter, so I bought the medium sized one in it's place. I had only had the tank filled halfway anyway since my turtle was only 1.5 inches at this point. Mind you I didn't realize how fast they grow, and had no idea that Its recommended to have a filter that can filter 2 to 3x the tank size. So I decided to keep both filters in my tank. One on each side. Even though I still don't reach the recommended filter size, my water now almost filled to the top, stays absolutely clean. Turtles are pretty messy so I still have to do the weekly cleanings and all that extra stuff that apparently those who spend hundreds of dollars on filters still have to do as well. I don't know if this is some kind of luck thing, I don't know if maybe my turtle just isn't that dirty (yea right, I see him)... but I'm actually not looking forward to switching out my filter for the 'recommended' filter size, as these filters work so good. I love them. They are both very quiet. Aside from the sound of the water falling back in.. I mean it sounds like a waterfall. Who doesn't want to hear a waterfall? I love it. This can also be prevented by raising the water level or lowering the filter itself. Basically the closer it is to the water, the quieter it is. Such a simple device, yet so beautifully sufficient. The little one stopped working at one point and I thought... welp there you go! Get what you pay for. But nope! Removed the base, pulled out the magnetic spring propeller and tube, cleaned it out and like magic it started right up as soon as I plugged it back in. Love how easy it is to replace the filters. The filters themselves are great and definitely hold on to some dirtiness. One thing I'll say is there is quite a bit of unused empty space. I now take advantage by adding some extra media, but I must say that these filters work great even without the extra. Love this filter and would recommend above any other filter. ### ⭐⭐⭐⭐⭐ 👍🏼 *by J***E on April 29, 2026* This fish tank filter has been a solid addition to my aquarium setup. It keeps the water clear and clean, and I’ve noticed a big improvement in overall water quality since using it. It runs consistently without much maintenance and helps maintain a healthy environment for the fish. It’s easy to set up and doesn’t require anything complicated to get started. The flow is steady and helps with circulation without being too strong for the tank. Cleaning it is simple as well, which makes routine maintenance much easier. Overall, it’s a reliable, effective filter that does its job well and helps keep the tank balanced and healthy with minimal effort. ### ⭐⭐⭐⭐ Big improvement *by E***G on February 5, 2026* Big Improvement over the previous model. My small tank came with the previous version of this filter and it has a quite significant design flaw that twice caused the unattended tank to lose almost half it's water. Essentially, if the filter was at all clogged with particulate, water pressure would cause the water level in the filter to rise to the point it would flow out of the tank on the clip holding the filter to the edge of the tank. After the second time this happened and a lot of luck that it didn't fry my power strip, I decided it was time to switch filters. While I was prepared to move totally away from Tetra due to my upset over the previous situation, I noticed while researching the change in holding clip. The new design obviously is in reaction to the problem I encountered as it now is architected that even if water were to move back onto the holding clip, it would drain down into the tank as the attackment to the wall is lower on the body. Since I pretty much liked everything else about the design, I decided to give the new version a try. Price-wise it was reasonable and the noise level is very low. Once I received it, it was easy to assemble. My one complaint would be that the box contained two suction cups, but there is no instruction on how they are to be used. That said, I was able to position the filter very easily and the updated design allows it to be placed in such a way that it doesnt interfere with the tank cover. That had been a big complaint I had about the previous design. It was very quick to assemble, get in place, and start using and the speed of the water flow seems appropriate for the smaller tank size. Cleaning is easy since it essentially is just replacing the filter periodically. They do recommend on a yearly basis cleaning the impeller, which should help it last longer. ## Frequently Bought Together - Tetra Whisper Internal Filter 20 To 40 Gallons, For Aquariums, In-Tank Filtration With Air Pump - Tetra Whisper Bio-Bag Filter Cartridges For Aquariums - Ready To Use BLUE, Large, 3 Count (Pack of 1) - TetraFauna AquaSafe for Reptiles and Amphibians 3.38 Ounces, Aqua-Terrarium Water Conditioner, Makes Tap Water Safe --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hr/products/2063017-tetra-whisper-internal-filter-for-aquariums-20-to-40-gallons](https://www.desertcart.hr/products/2063017-tetra-whisper-internal-filter-for-aquariums-20-to-40-gallons) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-05-24*