Whisper® Internal Aquarium Power Filters

Product No. 25816-01


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The Tetra Whisper internal aquarium filter is the ultimate in quiet, convenient 3-stage filtration. The dual-sided mesh of the Bio-Bag® catches debris and fish waste while the activated carbon absorbs odors and discoloration. Biological filtration is provided by the Bio-Scrubber. Bio-Scrubber's anti-clog design provides complete biological filtration with the convenience of less maintenance. Because the Bio-Scrubber has a solid back, water is forced to flow evenly over the bacteria-rich bristles. The filter is submersible. NOTE: The filter now comes with a clip to hold the filter. If suction cups are needed please contact Consumer Services at 1-800-322-1266.
Whisper® Internal Aquarium Power Filters is rated 3.3 out of 5 by 56.
Rated 3 out of 5 by from This filler and my betta I just bought the whisper 10i filter and I like it so far I set it up and it is working well but the water current is a little to strong for my veil betta fish and he is having a hard time finding somewhere to rest being I don't have much things for him rest on but I guess with this new filter I will have to get more
Date published: 2017-01-12
Rated 5 out of 5 by from Great filter My tank is nice and clean now.I bought mine at a store not on here. Mine only came with the filter. I didn't get the scrubber thing with mine.
Date published: 2017-01-11
Rated 4 out of 5 by from set up not quite obvious, information missing I just bought a Whisperquiet 20i unit and it seems to be working nicely. However it wasn't quite obvious how to set it up. I know there are only 2 parts but the plastic piece fits nicely into the slot which seems to be for the filter. To make it even odder there are two indents near the inside front that fits the plastic part but doesn't hold it in place. Ignoring those oddities and putting the filter into the rear slots and letting the plastic part sit loose seems to be correct but a clearer diagram would have avoided the issue. Nonetheless the unit did a fine job cleaning my tank once it started.
Date published: 2017-01-07
Rated 5 out of 5 by from Filter over flow I just need 2 know how 2 keep the filter from over flowing.
Date published: 2016-12-16
Rated 5 out of 5 by from Replacement I purchased one of these in August and now in December it decided it was not going to work properly. After doing all the trouble shooting I called and spoke to a rep. We went over everything and she decided I had a defective filter so....your company sent me a brand new one. Thank you so much...
Date published: 2016-12-10
Rated 2 out of 5 by from Not for Aquatic Turtles I bought this due to my big filter was just to much my hatchlings were growing and I still have a month before I get to move them home from college into my 40 gallon tank. I bought this filter so they had more room to swim and they do but the problem is it doesn't have a way to adjust it or extensions for reptiles I can't fill the water too much or they try to escape off the turtle docks... as well as my new dock suctions to the floor but can't cause the water level is to hight to but it's not stable nor does it stay in one place... I wish you made an extender or more than 3 holes so the water height wasn't so high so they had basking space .... so recommend not using this for turtles
Date published: 2016-11-30
Rated 5 out of 5 by from Great product! I bought two 20-40 gallon Tetra filters for my 20 gallon tank that have 4 goldfish. They were working fine until I woke up one morning and saw the water was a little cloudy. I put some clarifier in hoping it would help. The next morning the water was so cloudy I couldn't even see the fish. I took a water sample to Petco and she said it was ammonia and I bought something for that. Before putting it in I decided to do a 25% water change. I noticed instead of vacuuming up debris that I was getting sand! I then put the fish in another tank while I emptied the whole tank to get the sand out - even the filters had sand in them. Then I set it up again and the water has been crystal clear now. I solved the mystery of the sand: apparently one of my cats was standing on the cover at night dipping his dirty paws into the filter where it bubbles seeing the filter doesn't have a cover. I now cover the top of the tank with a piece of cardboard at night so he can't dip his paws in anymore. It is such a relief to see crystal clear water every morning now!
Date published: 2016-11-19
Rated 2 out of 5 by from Missing Bio-filter I have bought a 10i from Walmart and it is missing the bio-filter and grid. I went and check all the boxes in the store are missing the bio-filter! Another Walmart store I went is also missing all the bio-filters. Is it possible to have this part sent to me and find a way to prevent people from taking parts from the box.Thank you
Date published: 2016-10-12
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I received a Tetra micro filter as part of the Tetra 5gal Betta Aquarium kit that I purchased from Amazon a few weeks ago. I have it plugged in and assembled properly and the filter is not clogged. It doesn't run at all since day 1. Advice? 

Asked by: Omarrrrr
Remove the motor and slide the bottom cover off of it to pull out the impeller. Check for anything caught in the impeller or inside the motor, clean it if necessary, then re-seat it, and plug it back in. If it does not operate, please call us directly at 1-800-526-0650.BREX
Answered by: BREX
Date published: 2017-01-18

I just bought this filter and I was wondering if there's a way you can turn the current down?

Asked by: Ashanta
Thank you for purchasing this Tetra product! Unfortunately, no, there is no flow control on this filter. If your fish are having a bit of trouble adjusting to the flow, test your water quality to make sure there isn't something stressing them out. You can also place a cluster of tall plants in front of the filter to break up the flow rate for them.BREX
Answered by: BREX
Date published: 2017-01-12

My whisper filter is throwing water up and over the back of the tank, is there a way to fix this.

Asked by: Nate506
Your filter is adjustable so the top of it should be about one inch below the top of the tank. With it at this level, water cannot back out when the cartridge is clogged. Check and replace the cartridge, if necessary. Remove the motor and take the impeller out for cleaning in case it is clogged. If you need instructions on removing the impeller, please email us at techsupport.tetra-fish@spectrumbrands.com.BREX
Answered by: BREX
Date published: 2017-01-09

If I use two of the 40i filters would that be enough filtration for a 60 gallon tank

Asked by: Smiley52179
Thank you for your interest in this Tetra product! It should provide enough, yes, as it certainly has the flow rate. However, how much filtration will be enough is also based on the type of animals you will be housing. BREX
Answered by: BREX
Date published: 2017-01-04

How often should the filter cartridge be changed?

Asked by: JFK332
Thanks for asking JFK332! That depends on whether you have a fish or a turtle tank. For fish, approximately every 3-4 weeks. For turtles, it may be as often as every 1-2 weeks, depending on your feeding and maintenance routines.BREX
Answered by: BREX
Date published: 2016-12-08

How long should two whisper 40i filters on a 37gallon tank last? Does this filter come with a warranty?

Asked by: Captain Morgan
Thank you for your interest in this Tetra product! They come with a two-year manufacturer's warranty against defects. The filter systems typically last 5+ years. They require typical maintenance every month or two of course, to keep them operating for that long. Remove the bottom cover with a Phillips screwdriver, then pop the motor off of the filter body. Remove the bottom cover, pull out the impeller, clean it and swab out the inside of the motor with a q tip. If you tend to have hard water, please use distilled white vinegar. If you need a set of instructions with pictures detailing this, please let us know and we would be happy to email them to you. You can reach us at 1-800-526-0650 or techsupport.tetra-fish@spectrumbrands.com or via the Ask A Question feature on our site.BREX
Answered by: BREX
Date published: 2016-12-01

Can you decrease the flow of the Whisper 10i filter?

Asked by: Amylynd
Thank you for your interest in this Tetra product! Unfortunately, no, it does not have a flow control on it.BREX
Answered by: BREX
Date published: 2016-11-28

I change my EX20 carbon filters regularly but I'm not sure how often the bio-scrubbers should be cleaned. I just changed the filter and the bio scrubber has a white build up on the scrubbers. Should the bio scrubber be cleaned when I change my filter ?

Asked by: Ginger Snap
Thank you for your inquiry! We only recommend cleaning them when they appear pretty clogged. Otherwise, the build up on them actually helps to biologically filter the tank. For cleaning purposes, use water from the aquarium if possible. So for example, after a water change, take the bio scrubber out, and with an old, soft toothbrush, clean it off in the bucket of dirty water. That's all there is to it! Be sure to not use any chlorinated or really hot, really cold water.BREX
Answered by: BREX
Date published: 2016-11-17
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Whisper Internal Filter Instruction Sheet

Whisper 3i In-Tank Filter Instruction Sheet


Aquarium Size

Cartridge Size


up to 10 gallons



up to 20 gallons



up to 40 gallons