As an aquarium owner, you have different options for filtration. The usual filtration processes found in many aquariums are mechanical (the act of filtering water by physically preventing large unwanted particles from passing through), biological (the act of filtering water by breaking down harmful bacteria and organic compounds) and chemical (the act of filtering water by breaking down harmful chemicals to simple, non-toxic ones).
But aside from the usual processes, there is also the process called deionization, which is the act of removing mineral ions from the water that can be harmful to fish and other aquatic creatures
. Such mineral ions are copper, iron, sodium, chloride, etc. The deionization process is actually a physical one which involves resins that can bind to the mineral ions and thus filter them out from the water.
Some deionization filter systems are single step while others are dual-step. Some DI systems have a single stage, but you can convert it to a dual stage with the Spectrapure MaxCap 1-Stage Add-on Assembly System from Pet Store
. You can use this for majority of single-stage DI systems so that you can convert them anytime you wish.
The Spectrapure MaxCap 1-Stage Add-on Assembly System is the cheaper alternative to buying a dual stage DI system.
Max-Cap DI Retro-Fit Kit, 1 Sta, 10in Clr Cart, TDS Mtr, w/Filt Wr Everything you need for most systems to convert a single stage DI to a dual stage DI with MaxCap high capacity DI cartrdige.