Not content with having a successful new prop power head on the market. Hydor released yet another product, their Calcium reactor in the performer series. Having three models to choose, you’ll have options for your aquariums ranging from 198 gallons to 687 gallons. With the max height of the Â Â Â Â calciumÂ reactors of 23.6 inches. Hydor is saying mum on the price, but we expect these to be less than $300 for the cheapest model. They seem to be a great choice for us reef builders.