Review on MyfatBOSS 10 Fish Tank Filter: The Ultimate Aquarium Filter Cartridge for 20-40 and 30-60 Power Filters by Justin Larjin

I was pleasantly surprised when I treated my fish. I had to take out the filters to keep the charcoal from destroying the medication. My fish are huge and I had to have a filter for them. So I cut slits in the top of four of them to remove the charcoal. I was shocked at the amount of charcoal in it. I've bought various brands over the years and all of them had very little charcoal in them. This brand I bought contains a lot of charcoal. I am permanently switching to this brand for both tanks.