Whisper 40i In-tank Filter - Up to 40 gal.

SKU: 205654
Manufacturer: Tetra
MPN: AQ-65818

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The super quiet Whisper in tank aquarium or terrarium filter that is ideal for 20-30 gallon tanks. The Whisper in tank filter is easy to conceal inside your aquarium; hide it behind a plant or other decorative object and from the front it is practically invisible. Space-saving design can be flush with the wall and operates in as little as 2 in. of water, making it ideal for low water level environments like amphibian aquariums, terrariums or turtle tanks. Complete 3-stage biological, chemical and mechanical water filtration is provided from the same Whisper Filter Cartridges used in the famous Whisper Power Filter. Whisper Filter Cartridges contain precisely the amount of activated carbon and filter mesh area to provide superior aquarium filtration. UL listed.

For more info on Internal or Submersible Filtration, please see Internal Aquarium Filter Basics.


Includes MediaLarge Bio Bag
Flow Rate170 gph
Power Cord Length6 ft.
Warranty2 year Warranty
UL ListedYes
Max Tank Size40 gal.
Length4.25 in.
Width3.25 in.
Height9.5 in.
Internal Id


Click here to download the instruction manual from Tetra's website.

Ratings & Reviews

6 reviews

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It barely makes a sound and works wonderfully! I use it for my turtle (who makes quite a mess) and this keeps the water clear and smell-free. The only downside is the support, because it can be knocked off the wall of her tank so easily, but it shouldn't be a problem in a tank with only fish and gente-er creatures.
I highly recommend buying it despite of that.



Wish I'd been able to wait longer and get it at THIS sale price! But even at full price, it seems to be working very well.
I have a baby red eared slider in a pretty good sized tanks (hand-me-down, not sure how many gallons), and he is a tricky fellow so I have the water level relatively low, which means that the waterfall from the top of the filter to the water level does create some noise, but compared to the amount of noise the motor makes, the waterfall sounds like Niagra!! I'm sure if I had fish who couldn't climb I'd barely be able to hear it.
And the best part: I can use the same old BioBags my dad has had lying around for some old filter he used to use! Can't beat that ;)
All in all, it makes very little noise, keeps the water clear and fresh, and I would highly recommend it.
p.s.: I have the filter situated on the tank wall parallel to my bedroom door, which means that whenever I enter the room, he has himself planted nearly between the filter and the glass, and still hasn't managed to get himself stuck. I'd recommend it to anyone just for that!



I recently bought two of these filters and am so happy I did. I already knew about the quality of the product, but the price! Amazing! I'm so glad I took the time to look online and found this store. I will definitely do more shopping from them in the future.

Great Filter!!!


I have an expensive Eheim filter system in
tank but it just wasn't clearing the water so I
added this one and in just a few minutes it
already looked MUCH clearer!! I am very
impressed with it!! I would recommend it to



very happy with this purchase overall. great product/great price.



I purchased 2 of these for my 60 gallon cichlid tank. They are very quiet, which is nice since the tank sits right next to my bed! I compared prices with alot of other online shops as well as my local pet stores and this price was unbeatable!