Corner Box Filter for Aquariums

This is a corner box filter to use in an aquarium. I struggle with soft water in my tanks and I use this with crushed coral to maintain a buffer and a stable pH. After just a day of running this I noticed an increase in my buffer and pH. You can put whatever you want into the space though, from sponge filters to filter floss. It works with an Aquarium Co Op air collar which is required to use it and is about 4 inches long. I recommend printing with 3 walls and 75% infill to insure it sinks. There are three parts, the filter body, a spacer that goes inside and connects to the air collar, and a lid. To set it up, place the air collar and a piece of green tubing onto the spacer piece and place this inside the body. Connect air line tubing to the air collar, fill the body with crushed coral (or whatever media you would like), run the airline tubing through the lid and then place the lid onto the filter. It's a tight fit so that it doesn't fall off. Now you can connect more tubing p