difference btw, RO & UV

[kariina]

whats the difference between a RO and an uv sterilizer?

[Kurt_Nelson]

RO stands for Reverse Osmosis, and is a type of filtration done on tap water to make it pure. More or less, water is pushed through a really really fine membrane and the membrane only lets the pure water get through. People use RO (normally combined with a DI stage) to make pure water to add their salt mix to, and for freshwater top offs.

A UV sterilizer uses ultraviolet light to sterilize the water. It doesn't filter it, or take out any heavy metals - it just kills anything alive in it. UV sterilizers need regulated flow through them - if the flow is too fast, stuff isn't killed. People use UV to help kill off disease or any nasty things in their water.

[cmor1701d]

In addition to what Kurt said I consider a RODI unit to be essential. I have a UV unit which is not turned on. One of these days I will remove it from the system, but I have to run a new return water line to do that.

[melosu58]

As the others have said they are two entirely different things. One is a water filter and the other is a light that kills parasites and algea spores that travel through the lighted chamber. Read these.

Introduction to Aquarium UV Sterilizers

Choose the best reverse osmosis unit for your needs

How to Use Reverse Osmosis in Your Aquarium

BTW moving this to the General hardware and equipment discussion forum.