Review on Optimize Your Filtration with Seachem's The Bag Filter Media Bag by Donald Blasko

Unlike previous versions, this bag has plastic strips along the side and bottom seams that are almost 2.5cm wide. I'm assuming this is to reinforce the stitching, but this blocks water flow by about 10-15% of the bag. In any case, it should be on the outside of the bag, from where it can be easily removed. If you use the cable tie provided, you will lose about 25% of the bag's capacity when you close it. I turned the bag over to cut off the plastic and instead of using a zip tie I used a food saver to seal the bag and ended up with 2 bags, both larger than the pre-filled ones. If you ever need to replace your Purigen, which you shouldn't, you can cut the pouch open and reseal it with minimal loss of capacity.