Review on UPETTOOLS Fish Tank Filters: Silent Submersible Foam Filter with 1W Water Pump for 10-100 Fish Tanks - Aquarium Internal Filter by Brandon Bugg

I've added dual density filter threads to the outer chambers to capture most debris as a mechanical filter, partly to allow the sponges to form a layer of bacteria with less need for cleaning, and also because I can put it in in a hatchery and the slots are big enough for the juveniles to get in. For my aquarium I also had to cut about 1/2 inch of the outer tube so it wouldn't be too high above the waterline blocking the lid. So these are my required mods. The design is great and it works pretty well, as you can see from the picture it's already collecting junk. The suction cups are far enough away from the glass that the fry don't lag behind and get stuck, which is good. Even if it might take a little longer. I also wish there was twice as much k1 carrier in the central chamber because there is so little in there it's kind of wasted space that could be successfully tripled. In general, however, it is much better than a regular sponge filter. You will need to remove it on cleanup to keep your k1 media from floating, but that doesn't matter. In addition, it is almost silent except for the distinct gurgle. I wish they made both a smaller and larger version.