RO or Distilled??

[goochs]

Is there a reason why one should use ro water over distilled??
Is the a paper I could read on the subject??

Thanks
Phil

[Randy Holmes-Farley]

By Ro, you mean RO only, or RO/DI?

Distilled water is fine as long as it wasn't condensed from pipes that contain copper or other metals that might dissolve in the water. I do not know what is used commercially, or what metal levels are usually attained.

RO/DI doesn't have that problem, and is what many/most aquarists use.

[goochs]

well why I ask is because I can puchase I think ro/di water at major grocery stores and at the local walmart.. They all have those culligan machines setup and it shows the process as being ro/di.. at least the one at walmart does.
It was either that or use distilled. I tested the brand sold at walmart for copper and it was none. I haven't checked the ro with a tds meter yet but maybe next time I go to walmart. So have said I could use tap water to top off with as long as there are no chlorine but I find the nitrate level and the buffering of tap water to be quite high.

Thanks
Phil

[Randy Holmes-Farley]

Most copper kits don't read low enough to ensure safety. I would use the RO/DI or distilled from Walmart way before using tap water. :)

[goochs]

thanks for the help.. I'll do some test on both abd stay away from the tap..

Thanks again
Phil

[Randy Holmes-Farley]

That sounds good. :)

You're welcome and good luck!

[goochs]

:( Well I checked with the local wal-mart and the local grocery store which both have those machines, one is a culligan. Both are RO only no de-ionization so I guess it'll be the distilled for now. I did find a huge difference in distilled though.. the buffalo don's distilled is 6.6ph whereas the Great Value wal-mart distilled is consistant at a ph of 7.0

just some fyi info

Phil

[Randy Holmes-Farley]

The pH of perfect distilled water could reasonably be any value between about 5.5 and 7, due to atmospheric CO2.

Also, the pH pure water is not read well by kits or normal pH emters, so I would not rely on the measurements.