I am happy with my rx6duo, I know apexifd is selling his rx4. Calcium reactors are very basic in design, few key point you want to look for in a unit will be upflow design, ph probe, easy access for refilling the media. Those are the 3 main reasons that brought me to the vertex line. I love how the line fittings are all john guesst and the top is a screw off design instead of thumb screw which can be rather annoying. I do use a feed pump to eliminate clogging, it does raise the back pressure a bit but that why the vertex comes with silicone orings.
|