Deionized water?

[Nanoreefjoe]

Can I use just di water I my aquarium I will be mixing with Red Sea salt. It really all I have access to at the moment

[GMay]

It is not recommended. RO alone is better than DI alone as it is capable of removing more. DI is great for finishing off that lastliitle bit of ionic material in RO. DI alone will not last very long either and will be expensive to replace as frequently aas would be needed.

[AZDesertRat]

Distilled water is the next best thing to RO/DI and much preferred over plain RO. If it is a small system DI can be cost effective but for larger systems it is easier to justify buying your own RO/DI system since 89 cents a gallon or whatever adds up very quick when you are adding a lot of water.

 

RO is only 90-98% efficient at removing TDS. Distillation is almost as effective as RO/DI depending on the system so can provide nearly pure 18 megaohm resistivity treated water. One thing I always suggest is to buy yourself a good handheld TDS meter for around $25 so you can monitor the water quality of the purchased water. Most who use the WalMart purple cap gallon jugs of distilled water report the quality is very good and consistent.

[soeminpaing]

I have been thinking about distilled water too. Is distilled water free from copper? Most distiller has copper coil I think.

[Weasel Baron]

Erm... deionized =/= distilled. Deionized is the most you can filter your water, it is almost pure H2O... but any of the three (RODI, just DI, distilled) will be fine. RO alone tends to have a higher O2 and salt content as compared to RODI/DI

[tjwaggoner]

I hear this quite often about distilled water being done using cooper equipment. I highly doubt any large scale commercial distilliation set up that can distill water on a scale needed to supply wal Mart with enough would not be using copper. Almost all equipment that contacts food or food related items is stainless steel or plastic. Copper is expensive, soft, it oxidizes fairly quickly, it is a better conductor than stainless but that's not enough to offset the other problems it brings up when used to process foods.

I have an assumption as to why this is. People think distilliation and they think of old moonshine operations perhaps where copper is the usual suspect due to it being easy to bend, solder, repair.

I of course could be wrong but I would be seriously surprised if anyplace with the capacity to distill enough water for Walmart is doing it on anything other than stainless modern equipment.

Copper stills are pretty much relegated to liquor commercials for artistic/crafty purposes and documentaries on Appalachia.

Someone correct me if I'm wrong here, I just wanted to say something after reading comments about how distilled water is somehow inferior due it being processed on copper equipment.

[AZDesertRat]

Commercial distillation units use exotic metals like titanium or glass or epoxy lined metals in their stills. Copper has not been used in decades.

You are still at the mercy of the vendor though so owning a handheld TDS meter is a good idea.

 

I prefer RO/DI from your own system or a trusted source but there are many safe sources of distilled water. The drawback with distilled is some contaminants are condensed in the steam and make their way into the treated water but usually in very small quantiies. Good RO/DI si the better choice when possible but for small systems distilled water is a viable option.

[soeminpaing]

Yep. If I can't see, I dont trust. And believe me I have a friend back in my country before moving to states who repair copper distiller in US embassy. Dont know about commerical distiller though. Some traces of metal is good enough for humans but not for our precious little guys. And I drink RO water. And offer more expensive RODI water to these guys.