Fish enthusiasts are usually interested in the most recent or technologically advanced method of accomplishing a task such as filtration. The sponge filters, which haven’t changed much in the last 20 years, are a notable exception. The best sponge filters are basic devices that any fish keeper should have on hand!
A Quick Comparison of the 5 Best Sponge Filters.
What Exactly Is A Sponge Filter?
A sponge filter is exactly what it sounds like: a filter that mechanically captures particles of food and solid fish waste floating in your aquarium water using a fine or coarse sponge. Unlike HOBs and canister filters, sponge filters do not typically include filter media or chemically clean the water in a tank.
The terminology is where things get a little confusing for new fish keepers. While including stages for water-polishing sponges or being modifiable with a sponge filter tip, other types of filters are not sponge filters. Let’s go over the specifics so you can see what makes these useful filters stand out from the crowd!
What Is Included in a Sponge Filter Kit?
While there are many different styles and designs, all of the sponge filters that I’ve seen and used have the same basic setup. Some of the newer models have increased capacity for filtering media (more on this below), but this is not a standard feature. When you purchase a complete sponge filter system, you can expect the kit to include the following items:
- Sponge Tip– For the filter intake, use a coarse or fine spongy cover.
- Intake Tube– A plastic tube with holes through which the sponge tip fits.
- Central Tube/Outflow– Either part of the intake tube or connected to it, the central tube may also be the outflow where water returns to your tank or connect to a separate, adjustable outflow.
How Does a Sponge Filter Work?
Sponge filters are attached to the side of your tank or are weighted to rest on the rim. Water is drawn through the sponge tip, where debris is collected, into the central tube, and out the outflow back into your tank.
Sponge filters are used in aquariums to provide simple mechanical filtration. While healthy aquatic bacteria can grow in your sponge filter, they usually don’t provide much biological filtration unless they have a special stage designed to hold bio-media for an extended period of time. Despite their advertising, the majority of these filters are only one stage.
How Do Sponge Filters Get Their Power?
You’ll note that there’s one item missing from the parts list: a power source. You’ll need to pick and buy your power supply separately from the pack, whether it’s an air pump for a sponge filter or an aquarium powerhead. The lack of moving parts is the primary explanation for the low cost of these filters.
Using Sponge Tips With Different Filters
A finer sponge tip may be used to replace the plastic intake panel on a HOB or canister filter. This allows you to use your filter for very tiny or delicate fish and shrimp that would otherwise be sucked through the standard screen. However, if you don’t want to reduce the flow rates, you should use a coarser sponge.
Taking Care of Sponge Filters
Sponge filters have the added benefit of being incredibly simple to maintain. When it comes to regular washing, this is by far the most hands-off filtration device. You’ll normally only have to remove the sponge tip and clean it once a week or a couple of times a month (depending on how much debris is in your tank).
It just takes a few minutes to clean the sponge tip under running water, and then you can replace it on the intake and go about your day. The sponges, on the other hand, normally last about 6 months before needing to be replaced. The intake, core, and outflow tubes may need to be cleaned a few times a year, but that’s it!
Advantages of using Sponge Filters in Aquariums
There are some reasons why experienced aquarists keep sponge filter kits on hand, even if they don’t use them often or as their primary filtration method.
- Sponge filter kits are extremely affordable, and even premium systems seldom cost more than $20, to begin with.
- Replacement sponges are inexpensive, and they only need to be replaced every six months, resulting in very low overall running costs.
- They are extremely adaptable and can be used in freshwater and marine tanks of any scale.
- They’re a great way to add oxygen to your aquarium’s water.
- They produce little water current, making them suitable for low-flow fish such as shrimp, Bettas, and goldfish.
- Sponge filters are low-maintenance and need just a few minutes of cleaning once a month.
- They are suitable for use in hospital tanks or when medicating your aquarium because they (usually) do not contain filter material.
- Sponge filter tips also protect your other filtration device from harming small fish, fry, shrimp, or snails.
Sponge Filters Disadvantages
These filters have also some serious drawbacks, despite their many advantages. Although I recommend having an emergency kit on hand, there aren’t many cases where I’d use a sponge device as my primary filter, and here’s why:
- Sponge filters only offer one-stage mechanical filtration and are unable to extract chemicals or odors from aquarium water.
- Since the sponge tip is rinsed clean weekly to avoid clogging, it won’t provide much biological filtration to your tank.
- Further media compartments can give good bacteria more room to thrive in premium sponge filters in the long term, but still offer less space than other filters (or your substrate, for that matter).
- Sponge filter tanks need water modifications at least weekly, to remove toxins from the water except if your primary filter is used with another chemical purification system.
- Sponge tips can only filter some waste and can be blocked quickly in a dirty tank.
- You really can’t polish water like a HOB or a canister system and as the filter takes waste, the flow rate drops dramatically.
- You may need to clean the sponge tip more than once a week to keep the water flowing through the filter, depending on how thin or gross the substance is.
- While the sponge filter is cheap, you will need to purchase an air pump or power supply to operate the filter as well.
Selecting The Best Sponge Filter For Your Aquarium
Let’s bring it all together and discuss how to choose the best sponge filter for your aquarium! As compared to more complex filter designs, there isn’t much to think about when purchasing a sponge filter. Almost any kind will effectively remove debris from your water. However, here’s what to look for in the best.
A Reminder About GPH Ratings And Sponge Filters
Another significant distinction between sponge filters and other models is that they do not have a flow rating in gallons per hour (GPH). This is because the flow rate is entirely determined by the output of your air pump or powerhead, rather than the sponge filter’s design.
Sponge filters often don’t have a consistent flow rate because it decreases as the sponge tip picks up debris and then rises as it is washed. As a result, GPH isn’t a useful metric for comparing these filters to one another or to other systems.
- Regardless of the overall design of the filter, finer sponge tips clog faster and slow the rate much more than coarser tips.
- This is why, when using a sponge tip with a HOB/canister filter, the coarser style is preferable, as a finer product could burn out the motor if it clogs and you don’t catch it right away.
Best Product Reviews for Sponge Filters and Filter Tips
Because they are not high-priced items, there is a wide variety of sponge filters on the market, and many of them look nearly identical to one another. I wouldn’t worry too much about specific brands for these filters; instead, choose one with the features you require, one that will work with your power supply, and one that has readily available replacement parts.
1. UPETTOOLS Sponge Filter
Sponge filters are typically single-stage devices, but this upetstools alternative combines biological and mechanical filtration for longer-term use. It’s an excellent choice for raising fish and shrimp fry, and while hospital tanks don’t require bio-filtration, the Hydro can still be used for them.
2. Aquatop Sponge Filter Kit
Tank Capacity: Up to 60 Gallons
Dimensions: 5.5 x 5.5 x 8.5 inches
Power: Air Pump or Powerhead
This simple Aquatop system is a Classic for a reason: these high-quality filters have been around for years with only minor design changes! The weighted base secures the fine sponge tip over the intake, and the central tube serves as an outflow. You can also put this one in any part of your tank.
This versatile sponge filter kit can be used with an air pump or powerhead to help oxygenate your water as it bubbles through the outflow. I really like the sponge tip’s quality, and it’s the perfect size for catching the majority of the debris. However, replacement parts for this system are becoming increasingly difficult to come by.
3. AquaPapa Corner Internal Filter
Tank Capacity: 5 to 10 Gallons
Dimensions: 5 x 3.4 x 3.4 inches
Power: Air Pump
If you’re looking for a sponge filter for nano tanks, this intriguing hybrid system might be the one for you. It is an excellent sponge system for a 10-gallon or smaller setup. It is not a sponge filter, but rather a small internal filter with two water-polishing sponges and a small compartment for biological filter media.
This small filter fits neatly in the corner of your tank. An air pump draws water through a plastic screen and into the first compartment with the sponges. This isn’t the best system for raising fry or shrimp because they could get caught in the plastic screen, but it’s ideal for Bettas and other nano fish.
4. Huijukon Double Sponge Filter Kit
Tank Capacity: 10 to 60 Gallons
Dimensions: 5.9 x 2.4 x 11.1 inches
Power: Air Pump
If you want a versatile sponge filter that can be used in a variety of ways, I highly recommend Huijukon’s Double Sponge Filter Kit. This filter, with two high-quality sponge tips, can cycle twice as much water at once and is less likely to clog than any other system on the list. It’s also one of the simplest to keep up.
This filter includes optional canisters that can be attached to the sponge intake tubes. Fill these with your preferred chemical or biological media for added filtration power! This is an excellent choice for fry and shrimp tanks, hospital installations, and as a secondary filter for any freshwater or marine tank. This is my choice for a sponge filter!
5. Lustar Hydro Sponge Filter Kit
Another option is the Lustar Hydro Sponge Kit, which is a classically styled and basic filter that can be used with either an air pump or a powerhead. This is their mid-tier model, with a fine and easily clogged sponge tip. If you want a coarser reticulated sponge tip, you’ll need to upgrade to their Pro series.
This sponge filter is ideal for a fry tank or a breeding tank with a low bioload. The fine material will protect any eggs or babies from the filter’s tug. However, weekly cleaning is required to prevent the sponge from becoming clogged with debris. The frequency with which it is maintained will reduce its ability to provide biological filtration.
I hope you enjoyed this brief overview of sponge filters, and I’d love to hear your thoughts in the comments or on social media! Sponge filters are extremely useful regardless of the size or type of tank you keep, and these adaptable systems are ideal for raising delicate small fish, fry, and shrimp, as well as hospital tanks.
Don’t worry if you’re still unsure about which sponge filter is best for your home. These are cheap enough that you can easily upgrade if you don’t like your first choice.
- Personally, I prefer the versatile Huijukon Double Sponge, and I’ve been using the Fluval Sponge tip on my powered HOB and canister filter intakes for years.
- The Aquatop Classic is a great basic sponge filter that is ideal for larger tanks up to 60 gallons in size, but the Lustar is a better option if you prefer a finer sponge tip.