Why You Need a Pre-Filter Sponge for Your Aquariums
Are you looking for an easy and cost-effective way to optimize hang-on-back or canister filters? Pre filter sponges (or intake sponges) are a simple way to optimize your hang-on-back (HOB) or canister filter. This foam cylinder is simple and has a hole at the center that allows you slip it onto your filter’s intake tube. It works much like a socks. What good is a prefilter sponge? We already have an aquarium tank filter. Intake sponges offer surprising benefits such as:
– They provide more surface area to grow beneficial bacteria, which purify the waste chemicals in the water and make it safe for your fish to live in. Large openings in the filter intake tube can allow large objects to be sucked up and potentially damage the motor. The pre-filter sponge prevents things like baby fish, dwarf shrimp, little snails, plant leaves, and fish food from entering the filter. An intake sponge increases mechanical filtration to keep your filter media clean. This is because dirty filter media can cause problems in the system. We would rather have an intake sponge that we can easily clean than filter media that has been buried inside a canister filter.
Prefilter sponge is installed at the tip of a filter intake tub
Which Pre Filter Sponge Should I Get?
There are three sizes to choose from: medium, large, and mini. We purposefully designed our sponges with coarse foam with a greater porosity. This means that our pre-filter sponges do not remove super fine particles, but they block out most other particle sizes and won’t get clogged up as quickly. Our mini pre-filter sponge is best for smaller fish tanks and filters with slow flow, whereas the large pre-filter sponge is well-suited for bigger aquariums and filters with fast flow. To help you select the right size, see our chart that lists some of the most popular filters in the fishkeeping hobby:
Brand
Model
Type
Size
Notes
Quietflow LED10
Quietflow LED 20
Quietflow LED30
Quietflow LED 50
Aqueon
Quietflow 75 LED
Aquaclear 20
Aquaclear 30
Aquaclear 50
Aquaclear 70
Aquaclear 100
Use an O-ring, zip tie, or extra sponge to make it stay
C2
C3
C4
Use a zip tie to make it stay
107
207
307
407
FX4
Fluval
FX6
Canister
Slim S10
Slim S15
Marina
Slim S20
Mini
Emperor 400
Penguin 75
Mini or Medium
Penguin 100
Penguin 150
Penguin 200
Place the intake basket over it
Marineland
Penguin 350
Remove basket and use an O-ring or zip tie to make it stay
Tidal 55
Tidal 75
Seachem
Tidal 110
Large
WhisperIQ 20 / 30/ 45
Whisper EX20
Whisper EX 30
Whisper EX 45
Medium
Tetra
Whisper EX 70
HOB
Large*
To make it stick, use a thick zip tie or O-ring.
To transform our powerhead into a mini-power filter, a prefilter sponge can be attached to it. Simply attach two zip ties on the powerhead’s intake tray, trim the tails, then slide on the large prefilter sponge.
How to Install a Pre Filter Sponge
1. Remove the basket if the filter’s intake tube contains a basket that is larger than the tube. 2. The prefilter sponge should be positioned on the intake tube partially so that it only covers the tube’s tip. The sponge should be positioned at the very end of the intake tube so that water travels more evenly through the entire sponge and the foam does not get clogged up as quickly.
Oring to attach on the end an intake tube to prevent the intake sponge slipping
1. You can make the sponge smaller by using one of these methods:
An O-ring kit with many sizes is available. Place an O-ring that fits snugly on the intake tube about 1-2 inches (22.5-5 cm) away from the tube’s end. The O-ring should be placed on the tube. Slide the prefilter sponge over it. Attach a plastic zip tie around the intake tube’s end, approximately 1-2 inches (22.5-5cm) from the opening. The buckle should still be attached to the tail. For a snug fit, slide the sponge onto the zip tie attached to the intake tube. Cut a small rectangle from the coarse sponge pad and place it inside your intake sponge. Slide the intake sponge onto the tube, and make sure it fits securely.
Zip Tie Attached to the End of an Intake Tube to Keep the Intake Sponge from Slipping
Even if your intake tube is not the most common shape, you can still make a DIY prefilter sponge. Use a sponge pad to cut a piece of sponge that you can either place inside your intake basket, or wrap it around the entire intake using zip ties.
To see a video demonstration of how to install and properly fit a prefilter sponge, watch our tutorial here.
How to clean a pre filter sponge
The intake sponge is essentially like a trash can that collects fish waste, old food, and other debris in the water. Once a month or whenever you see the water output of the filter has decreased, make sure to “empty the trash” and clean your pre-filter sponge.
1. To scoop out the sponge from the water, use a plastic bag. This will ensure that it doesn’t spread to the aquarium and cause a mess. 2. Squeeze and wring out the sponge several times in old tank water inside the plastic bag. 3. The water that is dirty acts as mild fertilizer for plants. If you are able to, then pour the water onto the lawn or a houseplant. 4. Continue repeating Steps 2 through 3 until water in the bag is no longer very dirty. 5. Place the prefilter sponge back on the intake tube. 6. If there are lots of particles floating in the water, just wait an hour or so for the filter to clean it up again.
Adding an intake sponge to your filter is an easy way to upgrade your mechanical and biological filtration, while protecting your baby fish and invertebrates from getting sucked up. For beginners, our aquarium filter guide will help you choose the right filter for your tank.