Sponge filters, myths and truths

Aquarium and Pond Sponge Filtration myths and truths:

I have read several posts in forums and especially Yahoo answers about Sponge Filters. There is still a lot of misinformation about how a sponge filter works and is powered along with what they can and cannot do in an aquarium.

There are several models of sponge filters (and several brands, not all are even close to equal). There are sponge filters that work as pre filters for canister filters or HOB filters (where they substantially improve bio filtration during cartridge changes (not to mention they extend the life of filter cartridges allow less frequent changes). There are also sponge filters that work in ponds, aquarium sumps, or work as sponge filters for larger aquariums (the Hydro Pond ).

Where some of the misinformation comes in is how they are powered, many can be or are powered by pumps or power heads not just air pumps.

Another source of misinformation is their capacity as compared to other filters. You cannot compare a small cheap sponge filter model to an Aqua Clear 50 HOB filter. However a Hydro Sponge #5 powered by a proper air pump (such as a Fusion Air Pump) or a power head (such as a SunSun JP-23 or larger) will easily match the Aqua Clear 50 in bio capacity (or usually exceed it) and mechanical filtration (often chemical filtration is not necessary in a healthy established aquarium, I only use carbon in new aquariums or sometimes after treatment).
The Hydro Pond II or IV will easily exceed the Aqua Clear 110.
All these sponge filters cost much less besides!

And finally another source of misinformation is on comparing all sponge filters as the same.
I have used many different models and they are not even close to bio capacity or even flow rate with the same pump (air or water) attached.
I have “clocked” the fill rate in a measuring cup of different brand “seasoned” sponge filters and found definite variations.
I will also admit to trying different brands for cost reasons assuming a sponge was a sponge, however I quickly noticed the difference.

There are sadly many similar "knock offs" of the coming out of China (no surprise) representing patent infringements.
There is a reason that there are so many patent infringements on Hydro Sponge, they work!