DI water

[tresguey]

Where I work we have a laser jet to cut metal. It uses DI water to cool the nozzle. But it is not reverse osmosis water. Can I use this instead. it think from what I get out of my research is that the DI process is the process that clears up the phosphates. Is this true?

I'm on a budget for now say's the little woman at home so I can't install my own RO/DI system yet.

 

[btkrausen]

RO pulls out all the dissolved solids from the water....so it does all the cleaning.....I would think just running through DI would almost be as bad as not using it at all.

 

[tresguey]

I guess I am not understanding this then. Why is it they push DI if you only need RO? I was always told that the RO take out particulates and the DI removes phosphates. And I have heard is that Chemi-Pure adds DI resins to their media just to remove phosphates.

 

[Reef-a-holic]

For the most part RO and DI do the same thing but in different ways. Most source water has a high enough TDS that DI resin alone would be used up very quickly and that would get expensive in a hurry. RO membranes typically have rejection rates of about 96%-98% so the there is still some TDS left in the water. That's why most systems you see use both...the RO does most of the work and the DI removes the left overs that the RO didn't catch.

 

[JackoChang]

Interesting responses. Bob Fenner loves his DI only water.

Dang you WWM, I can't find it now. Consider this statement not valid....for now.

I did find this interesting post on WWM,
Deionization Question
Hello Wet web,
<Hello Mike>
Quick question. What kind of impurities does a DI system not get out of the water?
<DI units consist of two ion exchange resins. The DI process removes calcium, magnesium and other positive metallic ions. Basically what you have is mineral free water.>
Are they necessary to get out?
<Depends on your source water quality.>
Can I get away with using just a DI unit instead of a RO/DI?
<Yes, depending on your source water quality. If nitrates/phosphates are present, you will need to RO. DI systems alone are normally used where
high mineral content is in the water.>
Thanks for the help
<You're welcome. James (Salty Dog)>
Mike

 

[myzislow]

Interesting responses. Bob Fenner loves his DI only water.

Talk about an interesting response.....Link? More info?

 

[tresguey]

I will have to find out if there is a TDS meter on our DI system here at work. All I know is that it uses over 100 lbs of resin when they replace it.

 

[AZDesertRat]

Many applications use DI only and it is often a viable option as long as they monitor the effluent quality via conductivity or TDS. DI by itself generally will not last nearly as long as RO/DI since the RO portion does 90 to 98% of the work, kind of like pretreatment for the DI.
DI also does not remove things which are not electrically conductive so may not be 0 TDS even when fresh resin is installed since things like phosphates, silicates and nitrates are weakly ionized or electrically charged. Thye also do not register well on a hobbyist grade TDS meter so may be present at levels unhealthy to a reef system and you wouldn't know it.

Either way, the DI has to be much better than tap water PROVIDED it is maintained well and monitored well.

 

[CJO]

RO removes most of the bad stuff in the water and DI finishes it. You can do it DI only, but it is quite a bit more expensive as the resin gets used quickly.

CJ

 

[cdness]

Spectrapure is selling their refurb RODI units pretty cheap on sale...

When working with those budget minded folks, check the price of buying RODI water, Distilled water, and an RODI system and put it all together to show why it's cheaper to go with your own unit...