so whats the difference between ro & ro/di

[AlienAnchovies]

ive been looking into buying an ro or an ro/di system for my reef
the thing is i have no idea what di is or where i can find a system here in town
im remodeling my kitchen and thinking about placing it under the sink
i went to home depot and saw they had ro ssyems but nothing with the di option

[::pete::]

This should do it (http://www.spectrapure.com/faq_p0.htm#howdi)

[GaryP]

The problem with an undersink unit is where are you going to put 20-30 gallon of water that you'll need for water changes? The under sink units are also designed for small volumes and make water at a slow rate. I started off with a 50 gpd unit but quickly upgraded it to 100 gpd because it made water so slowly.

The main advantage of a RO/DI is lower TDS. An RO will get you down to about 10-20 TDS. An RO/DI with fresh cartridges will get you down to 0 TDS.

[::pete::]

Under the sink!! Thats where my 6 stage is and has been for more than 2 years. I fill a 300 gallon container for my freash water and when low wheel it to the sink and fill'er up. The same for water changes I use the water and put the container right back again to make my fresh water.

[BuckeyeHydro]

ive been looking into buying an ro or an ro/di system for my reef
the thing is i have no idea what di is or where i can find a system here in town
im remodeling my kitchen and thinking about placing it under the sink
i went to home depot and saw they had ro ssyems but nothing with the di option

"RO" and "DI" are two entirely different methods of purifying your tap water.

RO, or reverse osmosis, units run your tap water through a sediment filter, carbon (typically), and then a RO membrane. For ease of discussion, this of the membrane as a "mechanical filter" with VERY fine pores - all the way down to the size of a water molecule. So for the most part, it lets water through and not much else.

DI, or de-ioinization, involves running water through plastic resin beads that in this application, chemically bind with impurities in the water. If set up correctly, typically with an RO ahead of the DI resin, a RO/DI system will purify your water to a greater extent than an RO system alone.