DJ88's DIY square calcium reactor
The purpose of a Calcium Reactor is to create a constant supply of calcium in the reef environment. Numerous corals and invertebrates use calcium to build their skeletal structure, which depletes this element from the water column. Using a two part solution once a day is an alternative, but on larger setups it is more cost effective and efficient to set up a reactor instead. Below is the latest design I came up with which has worked quite nicely. It is easier to build than typical round reactors, and hopefully you can build one for yourself as well.