Is it ok to top off with distiller water?

[thesmokingman]

I'm surprised at the lack of basic high school grade science in some posts.

[Seiryoku]

I'm surprised at the lack of basic high school grade science in some posts.

 

Oh look, my post count just went up one. Just as yours did when you posted that. Wouldn't you know it, both my post and yours are absolutely pointless!

[amnesiak]

I believe RO/DI is significantly better than distilled. It's just a theory, but I'm sure someone could test it with a TDS meter fairly easily.

 

The reason lies in the containers and the amount of time spent within. Usually when you go get RO/DI or make it yourself, you use it pretty quickly thereafter, and put it into a heavy 5 gallon bucket (both good things). A distilled gallon of water in a thin plastic milk jug has been sitting in that container for quite some time.

 

No plastic container is completely solid. Leave one of those distilled water jugs in the sun for a day and tell me if it tastes like plastic! That taste invariably is something, and that's probably dissolved solids. The pure 0 TDS water is an amazing solvent, and captures free molecules from the plastic container as air creeps through the thin plastic. The thicker 5 gallon bucket plastic does not have as extreme of a problem. Glass would not have this problem whatsoever (stable crystalline structure).

 

Can anyone verify that 'Old' distilled water, maybe left out in the sun, or something like that, has a non-zero TDS? I'd really like to test this hypothesis.

[thesmokingman]

That's a bit unfair to distilled water? What's distilled water ever done to you?

 

Hehe... kidding aside I'd imagine that sure the clear plastic is regulated by the FDA to be safe for consumption. I'm not sure that plastics used for buckets, trashcans go thru the same regulations to ensure safety.

 

Anyways, there's some info here from a quick google. It's a lot of reading so I didn't bother.

 

http://www.plasticsinfo.org/s_plasticsinfo...57&DID=2605

 

“[T]he levels of migrants potentially present in beverages packaged in PET bottles are below applicable international extraction limits that are based on safety considerations and orders of magnitude lower than levels causing adverse effects in toxicity studies. The use by consumers of PET polymer in food packaging, therefore, is demonstrated and considered safe.”5

[AZDesertRat]

Good RO/DI is beter than distilled but it has nothing to do with storage containers or plastics. Distilled does not remove everything is the reason why, it may still contain volatiles which get trapped with the steam and condensed in the finshed water whereas RO/DI is almost an absolute barrier filter followed by deionization to remove everything down to about 18.2 megaohms resistivity with high quality systems.

Storage containers will affect anything stored in them including and especially RO/DI since it is extremely agressive and looking to get back to its natural "dirty" state.

[amnesiak]

Hehe... kidding aside I'd imagine that sure the clear plastic is regulated by the FDA to be safe for consumption. I'm not sure that plastics used for buckets, trashcans go thru the same regulations to ensure safety.

Agreed, it's perfectly fine for consumption. All of my 5 gallon buckets are 'food grade' so they are too.

 

But think about it, tap water is 100% safe for consumption (in the USA) and we wouldn't use it on our reefs, right?

 

Storage containers will affect anything stored in them including and especially RO/DI since it is extremely agressive and looking to get back to its natural "dirty" state.

 

Exactly what I was trying to say! So RO/DI>Distilled right off the bat, but buying distilled that's been sitting for a while, even worse, and I think the thin walled container adds to that 'even worse' part.

 

Distilled is more expensive (usually) than DI water, I have RO/DI or DI water available at LFS or one grocery store (I dont trust the systems in the other ones) for 40-50 cents per gallon. Plus it's less wasteful to use your own containers.

[Dani3d]

I read that distilled water can contain a lot of copper from the process of distilling water and the equipement used (metal) to produce it, not sure if it is true.

 

algeao grow? from what I read in this forum a lot of people have algea problem with all sort of things like cyano and diatom etc..and they use only RO/DI water...

 

So using that water does not garantee you will be free of any algea.

 

I started my aquarium a month ago with my tap water because I could not find an affordable RO unit and Walmart was too expensive at 2$ a gallon, and I don't have much algea problem. all I have is a bit of green algea which I even let grow on the back glass.

 

I would not use anything with any TDS for topping off though as this will concentrate anything that is in there anf if the TDS is not 0, then there is definitly something in there. Can be copper, can be calcium etc..

 

What would adding spring, or to go to an extreme tap water, to a system actually do? I've heard it promotes bad algea growth, but is that all?

[Dani3d]

did you calculated the cost of gas to go get the water?

 

Here walmart sell the deminerilized water to 2$ per gallon. I did the math and changing 2 gallons per week and topping off, it would cost me 20$ per months.

 

Wow..I quickly decided to buy my RO/DI unit for 130$ shipped. In about 6 months I will have gained my money back and at this rate the membrane will last like 3 to 4 years and the DI probably a year or more. MY last unit was still producing nearly 0 TDS after 6 months of using it (for my discus) and I was using 30 gallons per day! But our tap water here is only 100 to 130 TDS, so pretty soft.

 

With hard water, where people can mesure like 500 or so TDS, the membrane and DI resine do not last as long so this have to be calculated as well.

 

In my case, I will save huge amount of money, even if I had to pay only 69 cents per gallon, because here the cost of gas is making this much more expensive, especialy in winter to warm up the engine. On can store the water for a while but water is heavy and transporting it is a pain as well.

 

RO\DI all the way.

 

 

+1

 

I dont have a RO/DI unit and have only used bottled Wal-Mart distilled water for over 5 years. No problems yet.

 

Mark

 

p.s. I pay 69 cents a gallon. I did the math for a 3 year period using mid range RO/DI unit. Calculated in replacement DI, Carbon Blocks and Membranes based on manufactures’recommendations. For MY use it didn’t make any $$ diff on which way I went. Your mileage may vary.

[AZDesertRat]

Don't confuse TDS or Total Dissolved Solids and calcium carbonate hardness, they are two different things.

You can have low TDS and hard water or soft water and high TDS, they do not necessarily go hand in hand.

 

All membrane manufacturers recommend softened water for best membrane life and performance as calcium carbonate hardness is tough on a membrane and leads to scaling.

[Dani3d]

Of course not. My water has low TDS and low KH (4 to 5). GH is 7 and it's 100 to 130 ppm for the TDS.

 

I don,t think one can have a very hard water and have low TDS..where did you get that?

 

 

Don't confuse TDS or Total Dissolved Solids and calcium carbonate hardness, they are two different things.

You can have low TDS and hard water or soft water and high TDS, they do not necessarily go hand in hand.

 

All membrane manufacturers recommend softened water for best membrane life and performance as calcium carbonate hardness is tough on a membrane and leads to scaling.