Prevents small animals and debris from getting sucked up
Increases filter capacity
Uses coarse foam to extend time between cleaning

The pre-filter or intake sponge is a simple foam cylinder that is designed to slip over the intake tube of hang-on-back (HOB) and canister filters. The filter intake tube often has large openings, so use a pre filter sponge to prevent fish, shrimp, and sizable debris from getting sucked up and ruining the filter motor. Not only does an intake sponge clear up your water, but it also provides valuable surface area to grow beneficial bacteria.

Find out which sponge size to get and how to properly fit it to your hang-on-back or canister filter intake by viewing the Sizing Chart and Video below. (Click the "Show More" button to expand the Directions/Specifications section.)

Mini:
Intake hole: 0.5 inches
Diameter: 1.5 inches
Length: 2.75 inches
Pore Size: approximately 25 ppi

Medium:
Intake hole: 0.5 inches
Diameter: 2.5 inches
Length: 3 inches
Pore Size: approximately 25 ppi

Large:
Intake hole: 1.25 inches
Diameter: 3.5 inches
Length: 5.5 inches
Pore Size: approximately 20–25 ppi

Cleaning Instructions:
1. Use a large fish bag, ziploc bag, or pitcher to put around the sponge while inside of the aquarium.
2. Lift the water and sponge out to catch the majority of debris that comes off during removal.
3. Squeeze the sponge inside the container of aquarium water.
4. Discard the dirty water, get more water from the aquarium, and repeat until sponge filter is mostly free of debris. (If you're only using the pre filter sponge as a mechanical filter, you can also rinse it at the sink.)
5. Reinstall the sponge and wait for a couple hours for the water to clear back up from the debris released when removing and reinstalling.

Note: Depending on the filter's suction power and size of animal, tiny fry, shrimp, and snails can still get through the foam in some cases. We recommend using a filter with gentler flow when keeping very small animals.

Sizing Chart and Video

Pre-Filter Size	Filter Brand	Fitment
Mini	Aqueon QuietFlow LED 10; Fluval AquaClear 20; Marina Slim S10 / S15 / S20; Marineland Penguin 75
Medium	Aqueon QuietFlow LED 10 / 20 / 30; Fluval AquaClear 30 / 50 and C2 / C3; Marineland Penguin 75 / 100 / 150; Penn-Plax Cascade Hang-on-Back Filters; Tetra Whisper EX 20 / 30 / 45
Large	Aquatop CF 300 / 400 UV, FZ13, FZ27; Fluval 107 / 207 / 307 / 407; Marineland Canister 160 / 220 / 360 / 530 and Penguin 200; Penn-Plax Cascade Canister Filter 500-1500 and Cascade Max Flow; Seachem Tidal 55 / 75 / 110; Sicce Whale 120 / 200 / 350 / 500; SunSun Canister Filters
Large	Aqueon QuietFlow LED 50 / 75; Fluval AquaClear 70 / 100; Fluval C4; Fluval FX4 / FX6; Marineland Emperor 400 and Penguin 350; Tetra Whisper IQ 20 / 30 / 45 and Whisper EX 70; Oase Canister and Hang-on-Back Filters	Needs O-ring or zip tie (see video)

Sponge Filters

Pre Filter Sponge

Sponge Pad Coarse

Green Easy Flow Sponge Filter (coarse)

Black Easy Flow Sponge Filter (fine)

Black Easy Flow Sponge Filter (coarse)

Giant Coarse Sponge Filter

Filter Optimizing Pad