Pre Filters: How One Small Hack Transformed the Aquarium Hobby!
At Aquarium Co-Op, we won’t claim to have invented the idea of pre filters, but we were certainly among the earliest champions of their use, developing a wide range of pre filter sponges that fit most—if not all—common filter types. We have also created intake adapters for Seachem’s popular Tidal hang-on-back filters, as well as for the marineland hang-on-back filters, and Fluval canister filters, so a pre filter sponge can be easily installed on each.
Pre filters deliver so many benefits and solve so many problems (at so little cost) that it’s no wonder they’ve become something every aquarist takes for granted.
For starters, pre filters do exactly what the name implies: they act as gatekeepers, preventing anything and everything from entering your filter. That includes precious fry, fragile shrimplets, and of course, snails—both the “good” kind and the pests.
Beyond these obvious inhabitants, pre-filters also protect critters lower on the food chain: scuds, seed shrimp, and the countless other microorganisms that make up our beloved ecosystems. And if protecting these tiny creatures weren’t reason enough, consider what happens if they get inside the filter. While not all would perish, those that did could cause an unhealthy ammonia spike, undermining the very purpose of filtration.
Protecting small creatures from being sucked into filters is exactly why pre filters were created in the first place. Hobbyists of a certain age may recall hacking together their own DIY solutions for this very purpose. When Aquarium Co-Op began offering sponges designed specifically for the job, fishkeepers adopted them instantly. We make them in three sizes—like gym socks, there’s one that will fit no matter what!
Early on, we discovered that porous sponges outperform finer grades because they clog less frequently and maintain stronger flow. That also means you don’t have to service your filter nearly as often. We adapted accordingly, and now our coarser pre filters are the standard. Clearly, the benefits go beyond protecting your livestock—they protect your filter, too, even enhancing it by supporting stronger flow and greater biological activity.
As water passes through a pre filter, it becomes “seasoned,” creating an ideal environment for beneficial bacteria to thrive. In other words, you gain biological as well as mechanical filtration. Meanwhile, the sponge’s surface doubles as a buffet for invertebrates and nano fish, which are often seen grazing on it throughout the day.
For all these reasons, the pre filter has become a permanent fixture in aquariums around the world. At Aquarium Co-Op, we are champions of organic innovation, knowing even the simplest tools can transform one’s experience in the hobby. We want everyone to enjoy nature daily—and nothing exemplifies that credo more beautifully than the humble pre filter.