Review on 💧 Seachem Matrix Carbon 500ml: Powerful Water Purifying Solution by Latoya Harper

Will not fit Marineland's refillable media cassette. Which was my intended goal. It fits but doesn't stay inside. Everything gets spilled into the rear filters when you try to remove them for monthly cleaning or refills. It can get pretty ugly if it gets into the aquarium water, and a greedy big enough fish can mistake it for food and swallow it. So I wouldn't use it for refillable media cartridges. But I suggest putting it in a media bag first. Works much better ONLY IN THE MEDIA BAG! Save yourself the frustration and invest in these and media pouches instead of refillable media cartridges. However, this is the best charcoal I've used, it doesn't expire in 4 weeks like most. Takes very long.