I have the 250 and it's used on a 125 gallon reef. It has no problems keeping the alk and ca where I want it. The construction of the reactor is mostly molded plastic with some acrylic components, not all cast acylic like the competition. It does have some advantages though, the lid is a screw off top with a o-ring and a ph probe holder built in. Better than keyhole flanges etc. The water pump is a small powerhead not a pump like a eheim or mag like the competition.
The reactor is not as physically well built as a all cast acrylic model, but I don't plan on playing football with it
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