Whats the difference between RO/DI and Distilled ?

[Adamas]

What's the difference between RO/DI & Distilled Water and which one is best for our aquariums?

 

[Anonymous]

RO/DI is reverse osmosis/dionized. Distilled is distilled water. IIRC it is boiled off and the steam is allowed to condense and is collected. You need to be careful with distiled some is collected with copper plating, IIRC. RO/DI is better it is more pure. RO is a membrane that only allowes small particals to pass. DI is a reson. I'm really not sure of the chem.mechanical way it wirks.

 

[Len]

Distillation can actually be extremely pure, more so then RO/DI. But these are lab grade distillers and aren't what we normally see for sale. RO/DI is a lot more practical for home use.

 

[Anonymous]

Distillation work on the boiling point as the discriminating factor, RO use the molecular size, and DI use ionic affinity. Different principle, different pros and cons, and different purity. Best is use all three together, as in some labs, but for most purpose in this hobby, RO/DI is good enough.

 

[Dewman]

If you Look at a gallon jug of Sams Choice, Drinking Water, It mentions Reverse Osmosis on the label.
I do not remember which one it is.
There are three kinds of Sams choice water ( I think).

Distilled, Drinking, and something else.
They color code them like Milk.
Green tops are the good ones. I buy them for folks to use as topoff while I am away.
Then there is Dark Blue I think and maybe purple??. I never tried either of those due the chance of copper fouling in such a small tank over time.

 

[Adamas]

Guys I asked this question because I saw distilled water systems for sale, just like the RO/DI units. They are very similar, and thats why I wanted to know which is the best.

 

[Dewman]

Woops, I sent before I was done.

I was going to ask...

Were my worries about copper fouling all for nothing? Or is there some credability to this claim?