Cobalt AquaticsTotal Freshwater 20 oz - Ultimate Water Purification Media for Freshwater Aquariums | Removes Organics, Colors, Odors & Nitrates

This stuff is fantastic! Over the months that I’ve been using this in my two aquariums I haven’t lost any fish. First time I haven’t lost fish in months. It’s easy to use. Instead of reusing the product by soaking in Clorox water, I just start with a new bag of Cobalt.

I have well water in my 20 gallon tank that has a nitrate concentration of 30 ppm. Five ounces of the resin lowers the nitrate level to around 10 ppm. The recharging is ridiculous. You need a gallon of water and four cups of salt for each 2.5 ounces of resin. So about once a month I have place two gallons of water and 8 cups of salt in a large bucket to recharge five ounces of resin. You are much better off buying API NitroZorb. It is recharged in a cup of water and 4 tablespoons of salt. And it is $10 cheaper.