This is a laboratory grade dual chamber calcium reactor thats only bin used about 10 months and is in perfect condition. It was built by bill wann of aquarium engineering. It is a set it and forget it cal reactor it’s the best cal reactor money can buy. The reason I’m selling is I’m going a different rout and it requires two part. But this is a recycling unit witch means it recycles c02. It used only one ten lbs tank in the time I have used it. Price is firm for I don’t have to sell it. It also comes with a lifetime no hassle warrantee if u break it they will fix it. Pics on request. Payment required befor I haul it to swap. To expensive to carry around for no reason.