Pura (Magnavore) APU00414 3-Pack 300-Micron Media Bags for Aquarium Filter, 6 by 12-Inch

Absolutely great for purigen!

This product is as advertised and priced fairly. I am very happy with my purchase, let me explain.1. Nylon bags resist algae growth.2. Bag is nice and large for plenty of product, great for large aquariums.3. Tear resistant, I have Biomedia in one bag and with shifting and move around the bag has maintained its leak proof design.4. Good enough for the smallest of media. I have one bag with Purigen/matrix carbon and it contains the product.5. Comes three bags at a time.These are the best bags I have come across in thirty years of reef keeping.

Awesome stuff, 300 microns allow my Seachem Purigen to stay intact and the Velcro allows for easy media cleanup and removal.You get 3 bags instead of one bag for the Seachem bag at 9 dollars a bag, so economically the Pura bags make much more sense.I bought the 250ml Purigen and was able to use 3 bags for 3 of my filters for 13 bucks instead of 27 bucks if I want to go with the Purigen bags.Local fish stores do not have fine mesh bags more than 100 microns.So win win all the way.

Velcro seal makes these bags convenient, but they can leak smaller media since the velcro is at the very edge and leaves a small hole at the corners. I roll the top over to prevent this. Seems well made.

This is my favorite media bag of the several I've bought and tried. I particularly like the velcro closure seal. The fact that the bags are larger than most should not be a problem, as any unused portion of a bag can be folded over and tucked wherever it is convenient. And, the size allows you to spread the media enough to fill whatever area you want. Charcoal, of course, should always be rinsed a lot to get rid of inevitable tiny dust particles. I then pour the charcoal in the filter and I'm good to go, knowing that the fineness of the bag is going to minimize any particles getting through to clog subsequent polishing filters. After a month or so it is an easy task to empty the charcoal, rinse the bag and use it for whatever media you desire.