Distilled Water vs Deionised Water

[Micheal Donnellan]

Can some one tell me what effects using Deionised Water instead of Distilled water would have on the Laser tube. Am asking as having problem actually finding distilled here

[Brad Knight]

I can field this one...

Sometimes distilled water will still have sodium or other 'ions' in it depending on how it's distilled.

DI water is cleaned of all ions... I use DI water because I test for different ions (in my day job)

A lot of time the two terms are used interchangeably and in most applications it doesn't matter which is used.

[Sam Yerardi]

In my previous life as a laser design engineer we used distilled water for almost all laser cooling applications. Deionized water works as well. We would order pallets of distilled water at a time.

[Micheal Donnellan]

So it should be fine to use,
I thought distilled water was superior to deionised as no nothing in it at all.

[Mike Hood]

Distilled water is preferred to deionized water. Distillation removes both ionic and
nonionic organic contaminants. (more pure)

[Micheal Donnellan]

I did some looking up on distilled and deionised water for laser cooling. I found that both of them will damage stainless steel with deionised being the more damaging of both of them. This is not great news as my cooling system has a stainless tank. From memory this is possible the problem someone else had earlier with same cooler as me. Filtered water appears to be just as good without the damage to metal parts in the system.

[Sam Yerardi]

The main problem with not using DI or distilled is the increase of calcium, etc. in the water leading to clogging the water lines just like in your house. The efficiency and ultimately the life of the tube will degrade as the water flow decreases. This may not ever be a problem for you in your area. We used water cooling on CO2 designs as well as YAG and diode-pump designs and never had problems with distilled water. On all of our water systems, though, the reservoirs were always plastic and not stainless.

[Kim Vellore]

Yep you cannot run DI water in metal. DI or even the reverse osmosis water does not contain any ions and can easily knock off ions (dissolve) when in contact with metal. I assume you are recycling water with a chiller or a heat exchanger which will not matter because once the water has ionized it does not take more ions, for the volume of water you will have in a heat exchanger this will not be a problem.

If you are recirculating water you can use any water you want, there is only a fixed amount of dissolved contaminants you can have for a given volume of water and that is not enough to calcify and cause you problems.
In other words if you are recirculating water you can use any water without problems.

On an another note DI water when left in the open absorbs CO2 and makes it acidic It can even take CO2 through plastic. Then the Acidic water is more corrosive than plain tap water. All this applies only when you run this over a long time and not recirculating.
If you run a copper tube for your RO water you will have a distinct smell of copper in the water and the tube will have pitting in no time (I learnt this the hard way).

Kim