What Is The Best Filter For An Axolotl? – Complete Filter Comparison

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You are in the process of setting up your first Axolotl tank and are wondering which filter is the right one? Then you’ve come to the right place. 

For an Axolotl tank, you have the choice between a sponge, canister or Hang-On-Back (HOB) filter. The best choice for Axolotl aquariums are canister or sponge filters, because they have the highest biological effect and clean the water efficiently. 

The filters should be designed with as little flow as possible so that they don’t stress the Axolotl. 

Why do Axolotls need a filter?

The name “filter” is rather unfitting for most aquarium filters, as its main task is not to “filter” anything out of the water, but to biologically break down pollutants. 

Axolotls excrete in their feces waste products, such as nitrite and ammonium, which must be broken down or removed so that they do not exceed harmful levels. The excretion products are broken down by various bacteria, which settle everywhere in the aquarium and especially heavily in the filter material. 

The filter material consists mostly of porous material, in which the helpful bacteria can easily settle. 

Thus, the filter is more of a colony of bacteria that degrades harmful waste products from the axolotl than a conventional “filter.” 

Even though plants in the aquarium absorb some of the nitrate and much of it is broken down by the filter, the remaining amount must be removed by regular water changes. 

Tasks that the filter performs:

  • biological decomposition of excretion products of the axolotl (e.g. nitrite and ammonium)
  • adjustable flow – as low as possible at the bottom
  • filters excrements and coarse impurities out of the water
  • balanced distribution of oxygen, temperature and nutrients for plants

Since axolotls excrete a high amount of nitrite and ammonium and are sensitive to poor water parameters, it is especially important for them that the filter has sufficient capacity. 

In addition to cleaning the water, it is also important for the filter that the flow is as low as possible and barely noticeable at the bottom. Axolotls come from a very low current body of water and too much water flow will quickly cause stress. 

What types of filters are available?

There are 3 different filter types relevant for Axolotl tank:

– Sponge filters
– Canister filter
– Hang-On-Back (HOB) filter

Sponge Filter

Sponge filters are among the most used filters in Axolotl tanks. They are comparatively cheap and have a gentle current. If you have multiple Axolotl in your tank their biological effect might not be strong enough and you need to install a second sponge filter or clean them more often. Also they are not so good at filtering coarse impurities from the water.  
A sponge filter for a 20 gallon tank usually costs 10 to 25 Dollar.

Pros:

– inexpensive
– easy to set up
– gentle flow 

Cons:

– takes up space in the tank 
– regular cleaning 
– might not have enough biodegradation capability for multiply Axolotls 

Canister Filter

In contrast to the sponge filter, the canister filter is not located in the tank, but outside, usually in the base cabinet of the aquarium and is connected via tubes. Canister filters have a higher biodegradation capability than sponge or HOB filters and are therefore more suitable for Axolotl. The water current can be adjusted with a spray bar so that there is hardly any flow at the bottom. 

A canister filter for a 20 gallon tank usually costs 90 to 150 Dollar.

Pros:

– Flow can be controlled with spray bar
– Biological capability is stronger than canister and HOB filters
– quiet  

Cons:

– more expensive than sponge or HOB filters
– connecting tubes outside the tank to the filter (risk of leaks)

Hang-On-Back (HOB) filter

Another good choice for an Axolotl aquarium are Hang-On-Back (HOB) filters. They are easy to handle and especially good for beginners. The filter material and flow can be adjusted, so that the current is not too strong in the tank. Their biodegradation capability is also good and they dont take up space in the tank. 

A HOB filter for a 20 gallon tank usually costs 35 to 60 Dollar.

Pros:

– good biodegradation capability 
– low flow
– easy to use 

Cons:

– Usually a little more expensive than sponge filters

What is the best filter for an Axolotl tank?

All three types of filters, sponge, canister and HOB have their advantages and disadvantages, but most Axolotl owners have good experience with canister and sponge filters. 

As a rule of thumb, the filter should filter all the water in the aquarium twice per hour. With the various filters you can find these values under “maximum capacity” or it is directly indicated for which aquarium size it is suitable. 

Examples of suitable filters:

1 Axolotl, 20 gallon tank – Sponge Filter*
2 Axolotl, 40 to 55 gallons tank – Sponge Filter*

1 Axolotl, 20 gallon tank – Canister Filter*
2 Axolotl, 40 to 55 gallons tank – Canister Filter*

1 Axolotl, 20 gallon tank – Hang-On-Back (HOB) Filter*
2 Axolotl, 40 to 55 gallons tank – Hang-On-Back (HOB) Filter*

How often should I clean the filter?

You should clean a filter as little as possible, because every time you clean it, you lose helpful bacteria that live in the filter. The bacteria are important for the breakdown of the waste products of the Axolotl and the balance in the aquarium. 

Canister filters, for example, only need to be cleaned once every 4 months. HOB filters and sponge filters need to be cleaned more often. Sponge Filters need to be cleaned about once a month, one indicator is decreased bubbles due to the filter being more clogged. 

HOB filters need to be cleaned about every 2 to 3 weeks, although here too it is important to clean as rarely as possible. 

How often should the water in the Axolotl aquarium be changed?

A water change should be carried out weekly with approx. 20 to 30% of the tank water. On this occasion you can also vacuum up excrements and impurities with a gravel vacuum cleaner and remove algae from the glass. This, together with the right filter, should keep the water quality in your Axolotl aquarium within a healthy range.  

Can axolotls live in a tank without a filter?

In principle, it is possible to keep an axolotl in an aquarium that doesn’t have a filter, but it is not advisable. 

If you do not have a filter and exchange large amounts of water regularly, almost daily, the aquarium system cannot stabilize and you will have to be very careful that no harmful substances accumulate. The danger that the water parameters are no longer within the tolerable range for the axolotl is very high in this case. It is easier to install a filter and only check the water values routinely. 

Conclusion 

The right filter belongs to the basic equipment of an Axolotl aquarium to keep the water quality stable. Canister and sponge filters are particularly suitable for Axolotl. But HOB filters can also keep the water in your axolotl tank clean.