Best Filters For Nano Aquariums

Today we will cover and review my top aquarium filter choices for small nano aquariums. Some of these nano filters may be applicable for tanks up to 20 gallons depending on the number of fish and the presence or absence of aquarium plants. Let's begin by discussing what makes a good aquarium filter and what you should look for when deciding what aquarium filter to buy for your small tank. 

Recommended Sizes

All filters will have a recommended tank size range to help customers select whats right for them. For the most part, these recommendations are valid and will help in making a decision. They should be seen as a general guideline and are no means a requirement. When you are dealing with small, planted aquariums you can certainly use a smaller filter than what might be recommended on the box.    

Flow Rate / Turnover

An aquarium filters flow rate is often seen described as gallons per hour or GPH. The flow rate of a filter will also tell you what the turnover rate of your filter/aquarium will be. For example: a 100 GPH filter on a 10 gallon aquarium will have a 10x turnover per hour. (100 GPH / 10 gal aquarium). Some hobbiests say that you should aim to have a 5-10x turnover in order to keep fish safe from Ammonia (NH3) toxicity.  I would say this is a good idea if you have a large fish load and little to no plants in your aquarium. Since we are talking about filters for planted nano tanks, I don't feel the turn over rate is very important. It's more about finding a low profile filter that looks good, stays out of the way from a visual perspective and does the job you need it to do.  For these types of tanks, the filter is more needed for gently moving water around than it is for aggressive biological filtration.   

Capacity

As previously mentioned, filtration capacity is not so important when it comes to planted nano aquariums. All of the filters we will cover have more than enough room for the necessary bio and mechanical filter media to filter just about any nano tank setup you can think of. For most nano tanks, I like to focus mostly on biological media even though it's not that important... Here's a secret- Nano planted tanks in particular can be ran with no filter and limited flow, just depends on your plant selection, fish load and comfort/skill level.

Top 5 Nano Tank Filters Reviewed:

#5 - Aquaclear 20

The Aquaclear 20 is a standard hang on back (HOB) filter that is well known and used in the aquarium hobby. Several sizes of the Aquaclear power filter are available, although today we will focus on the 20. It's a 100 GPH filter that has a convenient sponge media basket making it easy to insert and remove your media. This back portion of the filter is quite large, making it easy to add additional bio media if you wish. I like to remove most of the included sponges and replace with ceramic rings or small lava rocks. There is also a fine adjustment knob on the top of the inlet making it easy to decrease the flow rate if your using it on a small tank. HOB's direct water straight down from the spill over and sometimes you might have plants nearby that you dont want blowing around, this makes preventing too much flow very easy.  

#4 - SunSun HW-603B

SunSun is known for their inexpensive canister filters. Don't be fooled by the cheap price tag, these filters are actually decent quality and come in a range of different sizes. This small external canister filter is rated at 106 gallons per hour and will be great for most planted tanks up to even 30 gallons. The SunSun features a  3 stage filter chamber with included sponges of different porosity. I like to remove two of them and fill the remaining space with some sort of bio media like ceramic rings. The included inlet and outlet can easily be swapped for glass lily pipes if you with to create o more fancy, seamless look. 

#3 - Oase Filtosmart 60

Oase canister filters are some of the highest quality available in today's market. the Filtosmart 60 is an 80 gallons per hour mini canister filter that features a decent sized split media chamber.  Sold separately for about 8 USD is a bracket/clip that will allow you to hang the filter on the side or back of your aquarium. This is a really cool feature that I wish was just included with the filter. The Filtosmart 60 is ultra-quiet and I've had mine running non stop on my 12 gallon betta aquarium for almost a year with no issues. Don't forget that Oase Filtosmart line has other larger filters; some of which have built in heaters. 

#2 - Azoo HOB

The Azoo hang on back filter are some of my favorite cheap filters for small nano aquariums. The Azoo 60 is a very compact 15 gph filter that has flow control and included sponge based media. There is also a slightly larger 150 model that is rated at about 40 gph is your looking for a little more flow. Either option is great for the super small nano tanks, I use the Azoo 60 on tanks 10 and under with great success. The low flow rate is perfect for tiny planted tanks where I don't want my plants blowing around and especially great for betta tanks. 

#1 - Dymax Slim Flo

The #1 pick on our list is a new offering from Buceplant, the Dymax hang on back filter line. There are three models currently: The SF-120 (30gph), the SF-240 (60gph) and the SF-500 (125gph). Think of these filters as a higher quality version of the Azoo's. They include the same great features previously mentioned but also have larger media volume and more flow rate options for a wider variety of aquarium sizes and styles.  

Helpful add-ons For Your Filter:

Hopefully you now have a good idea of what filter you would like for your nano aquarium. If you have any questions please leave them down below! Thanks for taking the time :)