Is deionized water bad for S/W?

[CptCrusty1]

I have a "friendly" disagreement with a colleague regarding water quality and the difficulty of S/W vs. F/W. I'm about to start building a S/W setup; however, he's insisting I stick with F/W since that's what I know. He says that he used deionized water in a S/W tank and couldn't keep anything alive. Says he read all kinds of stuff about how S/W tanks have to be really pure, etc.

He's well versed in F/W... and is the kind of person that things S/W is too hard.

Can anyone comment about the Dionizing of water and it's possible detrimental affects on a S/W community?

[aesl1982]

Is deionized water bad for S/W?

Rodi water is what is recomended for sw rodi normally test tds levels of around 0-2. Ro water test roughly 10-50.

[rage]

I think you probably have the terms mixed up.
Tap water (tds ~200) -> sediment filter -> carbon block(s) -> RO membrane = RO water ( tds = 20-30)
RO water -> DI resin = RO/ DI water (tds = 0-2)
You DO want RO/ DI water in salt water. If you can get the tds to 0, that is pure.

Salt water can be hard but it can get easier if you do things right.
I killed a lot of fish 3, 4 years ago when I started because of bad animal husbandry.
I still kill a few now because I buy fish that are not compatible such that they kill each other or I buy fish that are harder to keep (butterfly fish)

[flipside]

If you check the TDS with a meter, they are virtually the same thing (RO/DI and Distilled water). I've used it before, in a pinch; no negative side affects to the tank.

[CptCrusty1]

Ok dudes... I'm a S/W nooooooooob with a capital NEW....

Please esplain, Lucy... RODI? TDS?

[nightster]

Reverse osmosis/ deionized(spelling?) and total dissolved solids.

[CptCrusty1]

TDS - Water Hardness? My water is really happy, thus it's extra hard....

[mistahoo]

If I'm not mistaken, water hardness and TDS are two different things.

[AhKwaB]

The reason behind RO/DI water is to be able to add back and mix to your exact requirements.