What Does a Patented Aquarium Sponge Filter Mean?

With the flood of cheap (1) Chinese knock offs, (2) patent infringing copies (Patent 5203990), and (3) long time competitors that are simply less efficient; the answer is A LOT!

One thing all three have in common is a poor sponge material design, which is also how costs are shaved!
I have seen YouTube comments by persons who only know these sponge filters by the above noted categories, not by the use of a patented AAP/Hydro Sponge Filter.

With a poorly designed sponge, much of the muck that is held by the sponge is trapped in the outer part of the sponge. A good test is when the sponge is removed, a good portion drips back into the aquarium if not removed very carefully. Then when rinsing, it does not take much to clean these sponges.

With a patented AAP/Hydro Sponge, generally the same amount of muck might drip back into the aquarium upon removal, however the big difference is when rinsing and squeezing to get clean in a small bucket of used aquarium water (or de-chlorinated water), it often takes 2 or 3 water changes in this bucket for the sponge to come clean!!!

The picture below demonstrates the high density of sponge pores found in a quality sponge. This is unlike most every other sponge which have more in common with the foam in your couch cushion!

high density of pores found in a quality AAP Hydro aquarium sponge filter

Let's look at each of these in a bit more detail:

Cheap Chinese Knock Offs: Here we have often poor filter design combined with already noted poor sponge design. The result is poor flow patterns and inefficiency of the filter in both mechanical and biological filtration. Often resulting in less than 1/4 the capacity of better sponge filters. An example is the XY-380 often sold on eBay or Amazon

Patent infringing copies: Here we again still generally see a poor sponge used to save on production cost for much lower capacity of bio and mechanical filtration. HOWEVER because the patented interchangeable design has been copied, flow patterns and versatility are definitely better.
Sadly Hydro-Sponge has ceased battling many of these companies infringing on their patent here due to time and money involved (not to mention that while AAP/Hydro Sponge is 100% American made, it is nearly impossible to stop patent infringement in China for low cost goods).

What we can do is avoid these companies and stores that sell these.
Unfortunately in our often social media driven world, we have aquarium marketing schemes de-jour such as "My Aquarium Box" actively promoting just one such patent infringer. As well as popular YouTubers such as Aquarium Cop-op re-branding Chinese made copycats with inferior sponge material and claiming that only coarse filter material should be used as it is better when in fact in many cases it is not the best choice and more often than not, a combination of fine and coarse clearly is best.
We also have a popular blogger who has very well written articles on fish care and implies expertise with "Labs" in the title. Unfortunately, he too promotes Amazon Chinese knock offs. Worse yet, when confronted, he goes off on a "Red Herring" argument about how often AAP updates their page as a way to somehow discredit the content, which this has no bearing on the subject (as well the content on the AAP website has been updated often, in past on this subject, prior to the sale of the business, it was updated on average every 6 months which is far more than any other author of quality aquarium keeping information).

In the end, we need persons in this hobby who will listen to others who have been around a long time to mentor them and and then follow the trail of truth.

Long time competitors that are simply less efficient: This is where sponge filters such as the Lees, Hagen, and Tetra fall based on my mentors experiments. While these and others have been around for a long time, their flow patterns simply do not allow the versatility of use nor the flow rates of the patented AAP/Hydro Sponge Filter. These filters also do not use the quality of sponge material, albeit better than all the Chinese knock offs, thus lowering mechanical and biological sponge filter capacity