Distilled/RO/DI

[meatbar4]

What exactly is the difference
Thx
CC

 

[Len]

Distillation is the process of purification whereby a solution is sucessively evaporated and condensed to extract pure water from the heavier solids in the solution. In practical terms, H2O- which is lighter - is evaporated, condensed, and collected while the heavier solids are left behind. Distillation machines are not very practical for common applications, and hence you don't see any available on the market. Some purified, market-bought bottled waters are distilled.

R/O forces a solution through a semi-permeable membrane, "sifting" out larger molecules to form purified water. Although the membrane does not reject 100% of unwanted molecules, the water produced is, for all intensive purposes, pure enough for most consumers. Because of it's small size and low cost, R/O is the most practical water purification method for the average person.

Deionizatoin uses charged ions to strip minerals in a solution to purify it (often called softening the water since it removes primarily carbonates and earth metals). When used in conjunction with R/O, deionization can further purify the water beyond what R/O can do alone.

 

[Qwerty1]

The risk of using distillated water is that the installation used to produce it has alot of copper parts which could leave traces of copper in te water.
Personally i wouldnt take the risk.

 

[tinyreef]

i use a stainless steel distiller. i bought it off the net for about $99 plus shipping. works great but slow. 8 hrs for 1-gallon. otherwise many water bottle companies sell the 5 or 6 gallon bottles for about $0.80/gallon.

 

[Len]

FYI,

I contacted several copper distilleries before, and they've all told me that the amounts of trace Cu in the resultant water is minimal ... somewhere in figure of 5 ppb.

 

[Qwerty1]

But copper doesnt evaporate, so in theory the level keeps going up.

At least in my mind it does :wink:

 

[tinyreef]

you can use poly-filter pad in your filter to remove any trace of Cu out. it also removes lots of other nasties. or just use a stainless steel distiller.

 

[esmithiii]

Querty:

Do you know what ppb means?

The math is staggering. Suppose you take my situation. I have a 180G (200G total volume) and I add about 20 gal./week. Suppose I don't do water changes for 2 years. After 2 years, I would have about 57 ppb Cu. That is higher than NSW, but not toxic to invertibrates.

Suppose you do 15% monthly water changes. Then after 2 years you would have about 17 ppb.

Most copper test kits for aquarium use cannot read below .1 ppm, or 100ppb.

Keep in mind that I have exceptionally high evaporation. I think this example is a most extreeme case.

Ernie

 

[Qwerty1]

But what if the waterchanges are done with distilated water too?
They may say its "in the figure"of 5ppb but that means it could be 7 or 8 too.
Last but not least, i know alot of systems which are older than 5 years.

All together you will get a very different level after recalculating.

 

[esmithiii]

My calculations are based on using distilled water with 5ppb for water changes.

All in all, you would have to wait over 5 years to even see a blip on the home tests. My point is simply I don't think it makes a difference if you use distilled or RO/DI where copper is concerned.

How big is your tank and what is your weekly evap rate and I will re-run the numbers for you @ 8 ppb.

Ernie