I'm getting out of the hobby and selling my precious Schuran JetStream I Calcium Reactor. This equipment has worked flawlessly and looks awesome. I think it is best suited for tanks 100g or larger. I also have 2.5 bags (about two full loads) of unused coral media that you'll get with it.
The thing that is special about these Schuran Jetstream calcium reactors is that they are designed to be more efficient than others, so you get the most you can out of the CO2 you buy. This is why I buy this equipment. Below is a good explanation about the latest Schuran design that is setting the new standard for efficiency (clipped from http://www.saltycritter.com/calcium-...m-reactors.htm).
"The Jetstream calcium reactors are a totally new design and reach dimensions of efficiency second to none. Many users both professionals or hobbyists know that they can dissolve coralsand in much higher quantities than in any other reactors before if these have static or moved fillings. If necessary it is possible to dissolve one filling per month. Carbon dioxide is taken up by an injector system. Bubbles of carbon dioxide which have not been used are caught by a gas/water separator and are injected into the reaction chamber again. In this way not a single bubble can leave the reactor without having been used. Up to now, the rest gases, mostly nitrogen, has caused problems in every closed reactor, thus complicated and delicate degasing procedures have been necessary. The Jetstream reactors are the first which to make use of this gas in a profitable way: It has a beneficial effect on the water flowing through the coralsand thus hinder the system in accumulation of fine slick. The whole filling is evenly dissolved. As a result the speed of current in the system is enhanced remarkably without diminsihing the solubility for carbon dioxide. The outlet water is free of gas. "