The MarineLand Penguin filter is a hang on back, or HOB, filter. This type of filter hangs on the back of the tank, which means it’s out of the way and does not take up much space in the tank.
Sometimes these filters can be loud, but this filter runs quietly with only a gentle hum. It allows for mechanical, biological, and chemical filtration for the tank. This means that water is pulled from the tank into a chamber where it is then passed through filter media before re-entering the tank. The water goes through floss filter media, which is the mechanical filtration. It then is passed through activated carbon within the filter cartridge, which is the chemical filtration. The activated carbon helps to draw impurities and toxins, like ammonia and nitrate, from the water.
The MarineLand Penguin has a patented BIO-wheel which houses beneficial bacteria needed to keep tanks clean and healthy, which is the biological part of the filtration system. The BIO-wheel is made with surface area in mind, which allows for more beneficial bacterial growth. It also spins gently, creating a pleasant sound of running water as the water re-enters the tank. The suction produced by this tank is gentle and should not harm most fish or invertebrates, although small fry or shrimplets may get sucked into it without an external sponge filter.
Canister filters are a great option for heavily stocked or high-volume tanks. They need to sit below the level of the tank since the water will be pulled down from the tank and flushed through the filter before being pumped back up into the tank. This feature allows for the filter to be hidden from view, meaning it won’t take away from the aesthetic of the tank.
The Fluval Performance canister filter functions best with a sponge filter on the intake to catch large particles in the water. This will make it easier to clean when the time comes and helps protect small tank residents, like fry, from being sucked into the filter. Like HOB filters, this filter provides mechanical, chemical, and biological filtration. A bonus of this filter is that the large size allows for the filter to be packed with bioballs or ceramic rings to encourage the growth of good bacteria.
The newest version of Fluval’s Performance canister filter has been made quieter by 25%, meaning it won’t stress fish or create excessive noise. To start this filter, manual pumping is required but once this has been done it should not need to be done again unless the filter is turned off. The Fluval Performance filter is energy efficient and has a very minor impact on energy costs.
This type of filter is called a wet/dry filter, also known as a sump. It is similar to canister filters in that the filter media can be chosen at the owner’s preference, so bioballs, ceramic rings, or something else entirely. These filters are powerful and are the best option for overstocked tanks. The Kollercraft Rapids Pro filter returns oxygen-rich water to the tank and removes ammonia and nitrate along the way. This pump is so powerful that it may reduce the need for water changes, even in overstocked tanks.
The Kollercraft Rapids Pro is suitable for freshwater and saltwater aquariums and does not strain energy resources. This filter comes with the added bonus of a UV sterilizer, which can decrease green algae in the water and even kills some parasites. Be aware that UV sterilizers may need to be turned off when using certain medications or chemicals in tanks.
Undergravel filters can be a great option, especially in goldfish tanks, because of their ability to provide surface area for beneficial bacteria and filter waste. While gravel is not recommended for goldfish, undergravel filters can be used with pebbles, bio growth clay pebbles, or even sand. A powerhead pump can be paired with an undergravel filter to reverse the water flow, allowing for the addition of a pre-filter sponge to catch large debris.
Sponge filters are nice on their own but can also be a great addition to other types of filters. Sponge filters sit in the water at the intake and catch large debris, as well as ensuring small fry, shrimplets, and sick or weakened fish do not get sucked into the filter. In fact, these are a good option for quarantine and nursery tanks.
The Hygger Double Sponge filter has two sponges that water passes through. The water then passes over ceramic balls, which allows for the growth of beneficial bacteria. These are not the best option for large or overstocked tanks unless added to another type of filter.
Featured image credit: Alexander Geiger, Shutterstock
Do Goldfish Need a Filter?
The truth is, goldfish need to have a filter, and you need to have one for your own sake as well.
Goldfish produce toxins (through their waste and respiration) that accumulate in the aquarium and can cause all kinds of major problems.
The purpose of a filter is to supply a multi-pronged approach to get rid of the nasty toxins and keep your goldfish safe using a combination of mechanical, biological and sometimes chemical filtration.
Theoretically, goldfish could live without a filter on one condition:
Huge daily water changes.
Those would effectively remove the toxins and keep the water safe for our finned friends.
But it isn’t practical for most people to be doing this for their aquariums! We have things to do besides carrying buckets all the time and paying a massive water bill.
Filtration stands in the gap between a dirty tank and going crazy with water changes.
“Think of your goldfish filter as a mini sewage treatment plant.” – Goldfish keeper
There are 3 things to consider when it comes to picking out the best filter specifically for your goldfish.
Common filter options like hang on back filters and canister filters hold less media.
That’s why everyone is always hyping having a high volume of water flowing through them, because without it there isn’t enough oxygen to keep the bacteria alive.
But guess what?
While athletic breeds like Common and Comet goldfish don’t mind current, fancy goldfish don’t like a strong current in the water.
Their fins are longer and catch the water current, blowing them around the tank or causing them to struggle to stay in place.
Sometimes they give up the fight and hang in a corner or sit at the bottom. This STRESSES the fish which weakens their immune system.
And what does a low immune system lead to…?
Many filters are designed in such a way that they require frequent cleaning to stay clear of debris.
If debris is allowed to build up in a filter, in certain conditions it can become incredibly toxic.
Mulm (white gunky gross buildup) and sludge (brown gunky gross buildup) stress the immune system as they become loaded with bad bacteria, leading to sick fish.
Filtration is more than just trapping particles of fish poop or having clear water (though those are nice of course).
Filtration is about completely eliminating ammonia (the #1 killer of aquarium fish in the world) and nitrite, turning it into the much safer nitrATE.
To get rid of ammonia you need beneficial bacteria that consume it and turn it into a far less harmful substance. A good filter has got to have lots of room for beneficial bacteria to grow – or it they can’t do their job.
Let’s face it:
The majority of filters on the market today are way too small to be effective for our “messy goldies.”
They just lead to a false sense of security for the hobbyist.
So choose one of the high performing brands above for best results.
What kind of filtration you choose depends on your lifestyle, the kind of fish you own, and the needs of your aquarium as a whole.
There is definitely a trade-off with the more discreet filtration systems being not as efficient or safe for the fish, and the more powerful ones being more expensive or visible.
My advice has been and always will be put the fish first, then worry about looks afterward.
What is best for your pets?
In the end, a healthy, well-filtered aquarium will support healthy, happy goldfish and save you extra work.
What Do You Think?
Do you wonder if your goldfish have enough filtration to balance out your water changes?
Have a question about how a certain filter works, or a preference for your tank?
Brooke Billingsley spent nine years as a veterinary assistant before becoming a human nurse in 2013. She resides in Arkansas with her boyfriend of five years. She loves all animals and currently shares a home with three dogs, two cats, five fish, and two snails. She has a soft spot for special needs animals and has a three-legged senior dog and an internet famous cat with acromegaly and cerebellar hypoplasia. Fish keeping has become a hobby of Brooke’s and she is continually learning how to give her aquarium pets the best life possible. Brooke enjoys plants and gardening and keeps a vegetable garden during the summer months. She stays active with yoga and obtained her 200-hour yoga teacher certification in 2020. She hosts a podcast focusing on folklore and myth and loves spending her free time researching and writing. Brooke believes that every day is an opportunity for learning and growth and she spends time daily working toward new skills and knowledge.