There are many types of filters that use a box hanging off the back of the aquarium to mechanically filter the waste. These are called hang-on-back, HOB, or cartridge filters.
Aquarium Filter Test: how “good is a filter?” Most focus on ammonia and nitrite oxidation but forget Crystal-clear water!
Any discussion of ANY filter requires a disclaimer. ALL commercial filters almost without exception tell the owner to replace the filter media! Replacing the Filter Media is a Big SCAM!!!
There are several varieties of a “Proprietary Product” called Chemi-pure. These are simply mixtures of the products below with very high price tags.
Poly-Filter is an extremely expensive ($45 for a one square foot piece!) fibrous pad material that is commonly used in filters. This material is basically disposable baby diapers per the chemistry in the patent.
Seachem Purigen is an interesting well hyped extremely expensive ($45-$60 for one liter) product that is supposedly unlike any other filtration product.
Phosphate removing granules work! So if a 95% water change doesn’t remove the phosphate, phosphate-removing granules are a very good option.
Zeolite Ammonia Removing Granules in the Aquarium in the aquarium is to expensive and it removes just too little compared to a normal functioning filter!
There are two distinct uses for deionizing resins. One is to treat water for a water change and one is to directly treat the aquarium water to remove nitrates or ammonia. Neither use is a very good use of monetary resources, to put it mildly.
Activated Carbon in an Aquarium Filter has very limited use. The way manufacturers advertise is a scam!