---
product_id: 2063017
title: "Whisper Internal Filter 20 To 40 Gallons, For Aquariums, In-Tank Filtration With Air Pump"
brand: "tetra"
price: "$124"
currency: NZD
in_stock: true
reviews_count: 9
category: "Tetra"
url: https://www.desertcart.nz/products/2063017-whisper-internal-filter-20-to-40-gallons-for-aquariums-in
store_origin: NZ
region: New Zealand
---

# 170 GPH filtration power Ultra-Activated® carbon odor control Easy Bio-Bag cartridge swap Whisper Internal Filter 20 To 40 Gallons, For Aquariums, In-Tank Filtration With Air Pump

**Brand:** tetra
**Price:** $124
**Availability:** ✅ In Stock

## Summary

> 💧 Keep it clean, quiet, and classy with Tetra Whisper 40i!

## Quick Answers

- **What is this?** Whisper Internal Filter 20 To 40 Gallons, For Aquariums, In-Tank Filtration With Air Pump by tetra
- **How much does it cost?** $124 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nz](https://www.desertcart.nz/products/2063017-whisper-internal-filter-20-to-40-gallons-for-aquariums-in)

## Best For

- tetra enthusiasts

## Why This Product

- Trusted tetra brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Optimized Oxygenation:** Air pump bubbles oxygenate water while filtering, promoting a healthy aquatic environment for your fish.
- • **Effortless Maintenance:** Large, easy-to-change Bio-Bag cartridges keep upkeep simple and hassle-free—no more filter fumbling.
- • **Triple-Stage Filtration:** Combines air-driven water flow, dual-sided mesh, and activated carbon for crystal-clear, odor-free water.
- • **Whisper-Quiet Efficiency:** Operates silently so your aquarium stays peaceful and your workspace distraction-free.
- • **Space-Savvy Internal Mount:** Mounts inside the tank allowing flush placement against walls—perfect for sleek, modern setups.

## Overview

The Tetra Whisper 40i Internal Filter is a compact, in-tank filtration system designed for 20-40 gallon aquariums. It delivers up to 170 gallons per hour of quiet, efficient water filtration and oxygenation through a triple-stage process involving air-driven flow, dual-sided mesh debris capture, and Ultra-Activated® carbon odor control. Its internal mounting design allows tanks to sit flush against walls, while large Bio-Bag cartridges simplify maintenance. Trusted by aquarists for decades, it balances performance with convenience for a pristine aquatic environment.

## 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: I love these. Still going strong after 5 years. Bigger one and smaller one - I have used these for so many years for little tank setups and my turtle and snails etc. Always work super great and super quiet! Plus they are cheap. No brainer imo. I'm sure theres a faulty one here n there as with anything but keep the propeller clean like any other pump and dont let the filters get too overflowing clogged and you'll be happy I promise. Also with filters of any kind try to get one rated for more than you actually have so the filter doesn't get overwhelmed. Even the filters are cheap for a box of 12 for like $13. Cant go wrong!! 10/10
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.

## 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 |
|---------------|-------|
| ASIN | B0002DHYH2 |
| ASIN  | B0002DHYH2 |
| Age Range Description | all ranges |
| Batteries | Product Specific batteries required. |
| Batteries  | Product Specific batteries required. |
| Best Sellers Rank | #2,503 in Pet Supplies ( See Top 100 in Pet Supplies ) #5 in Aquarium Filters |
| Brand Name | Tetra |
| Color | Black |
| Customer Reviews | 4.2 4.2 out of 5 stars (22,105) |
| Date First Available | June 9, 2004 |
| Date First Available  | June 9, 2004 |
| Department | Unisex-Adult |
| Department  | Unisex-Adult |
| Directions | See label for details |
| Included Components | Whisper In-Tank Filter 40i (upto 40 Gal) |
| Is Discontinued By Manufacturer  | No |
| Item Dimensions LxWxH | 5.85 x 5.09 x 10.29 inches |
| Item Package Dimensions L x W x H | 14.53 x 11.5 x 6.22 inches |
| Item Weight | 1.5 Pounds |
| Item model number | AQ-65818 |
| Item model number  | AQ-65818 |
| Manufacturer | Tetra |
| Manufacturer  | Tetra |
| Material | 100% Polyester |
| Model Name | Whisper Internal Filter |
| Number of Items | 1 |
| Product Dimensions  | 5.85 x 5.09 x 10.29 inches; 1.5 Pounds |
| Size | 20 - 40 Gallons |
| Specific Uses for Product | Indoor |
| Target Audience Keyword | fish |
| Warranty Description | See label |

## Images

![Whisper Internal Filter 20 To 40 Gallons, For Aquariums, In-Tank Filtration With Air Pump - Image 1](https://m.media-amazon.com/images/I/81W+Z3JdNIL.jpg)

## Available Options

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

## Customer Reviews

### ⭐⭐⭐⭐⭐ I love these. Still going strong after 5 years. Bigger one and smaller one
*by D***T on December 19, 2025*

I have used these for so many years for little tank setups and my turtle and snails etc. Always work super great and super quiet! Plus they are cheap. No brainer imo. I'm sure theres a faulty one here n there as with anything but keep the propeller clean like any other pump and dont let the filters get too overflowing clogged and you'll be happy I promise. Also with filters of any kind try to get one rated for more than you actually have so the filter doesn't get overwhelmed. Even the filters are cheap for a box of 12 for like $13. Cant go wrong!! 10/10

### ⭐⭐⭐⭐⭐ 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.

### ⭐⭐⭐⭐⭐ Works perfectly – great quality
*by C***A on February 10, 2026*

This product works perfectly and does exactly what it’s supposed to do. My aquarium looks cleaner and healthier, and everything runs smoothly. Great quality, easy to use, and worth every dollar.

## 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.nz/products/2063017-whisper-internal-filter-20-to-40-gallons-for-aquariums-in](https://www.desertcart.nz/products/2063017-whisper-internal-filter-20-to-40-gallons-for-aquariums-in)

---

*Product available on Desertcart New Zealand*
*Store origin: NZ*
*Last updated: 2026-03-01*