# Is it ok to use RO/DI water?



## psychedelicwonders (Oct 15, 2008)

I know RO water is suggested, but I have a 4 stage RO/DI filter from my reef setup.

Is it ok for me to use RO/DI water, or is that too sterile and too filtered?

I've read that too sterile of water and too filtered can actually leach good nutrients OUT of the bodies of the PDF.

thoughts?


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## postal (Aug 12, 2008)

I believe the common thoughts are:

1 remove the DI filter and you're fine.

2 If you're misting a tank and plants or adding water to a false bottom setup, DI is fine.

3 If you dont have a false bottom, and you're filling a stand alone "pool"- dont use DI.

Basically, you dont want the frogs to soak in DI. However, as soon as that water hits soil, it will pull tannins out of the soil, and is fine.

I just started using RO in my false bottom tanks. Parents got a filter setup, so I fill up some jugs when I go over there.


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## Richard (Aug 14, 2008)

Just out of curiousity, what is the problem with DI water?


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## Bcs TX (Sep 13, 2008)

What about spring water? Should the tablets to remove chlorine for fish tanks be used?


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## Catfur (Oct 5, 2004)

I think the general consensus is more along the lines of "as long as you don't dunk tadpoles in straight RO/DI water, it's okay for just about any other use."


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## FrogOly (Oct 5, 2007)

Richard said:


> Just out of curiousity, what is the problem with DI water?


DI removes just about everything from the water, and the resulting water wants to add ions to it, making it very 'aggressive'. A home DI may not be that pure, depending on the age of the filter, and the quality of the water going in it. If the DI filter goes too long, it could even add things back into the water.


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## Laxgoal100 (Sep 9, 2008)

what about DI water bought in gallons from the store... thats what i use.


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## psychedelicwonders (Oct 15, 2008)

Thats what I was worried about was the DI taking too much out of the water and then trying to leach nutrients back out of the PDF.

What is a tannin and why do the ions in the RO/DI water want to extract them from things?

The filters on my machine are new, so that isnt an issue.

i can always just add a T valve on the RO part so that I can extract water from the machine before it hits the DI area.

But would still like to hear others ideas on this one.

Seems they can vary.


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## postal (Aug 12, 2008)

Tannins are that stuff in wood/coco/peat etc that turn water brown.

Once DI is able to get *something* added to it, it isnt pure anymore, and it isnt trying to pull anything into it. The water in a bowl could be a problem, but if it was poured into a false bottom, through the soil, would be perfectly fine.

Spring water- I think a lot of people use it and it's fine as is. Though some bottlers may add calcium to it which is not good for moss. Check the label to see if it's spring water, or if minerals (for taste) were added to spring water.


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## FrogOly (Oct 5, 2007)

psychedelicwonders said:


> Thats what I was worried about was the DI taking too much out of the water and then trying to leach nutrients back out of the PDF.
> 
> What is a tannin and why do the ions in the RO/DI water want to extract them from things?
> 
> ...


Not only are new filters important for DI, but the quality of the water going into the unit. Things like hardness, iron, and hydrogen sulfide gas degrade the surface of the RO membrane, allowing more impurities to pass through it, and many impurities passing through the RO membrane are removed by the resin in the DI cartridge. The more impurities going into the DI cartridge equal less useful life of the DI cartridge. 

Pure water is commonly known as the universal solvent, and by nature wants to add 'things' to it, and can pull 'things' through a membrane like a frog's skin.


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## Ed (Sep 19, 2004)

FrogOly said:


> Pure water is commonly known as the universal solvent, and by nature wants to add 'things' to it, and can pull 'things' through a membrane like a frog's skin.


This is something that comes around all the time in various forums and articles. This is only a problem if the frogs cannot get out of the DI/RO water and even then the frogs are able to compensate for it as they can reabsorb calcium and other ions from the water through thier skin. It would divert some calories from other metabolic processes (which to some extent is not that big a problem since many frogs are obese) until the frog was able to get out of the water. 

The water does not "leach" ions from the frog, instead the frogs have to spend energy pumping the excess water out of thier cells and body which can cause a loss of ions. 
Any water that has a osmotic pressure of less than the frog is going to move along the osmotic gradient causing the frog to spend energy to deal with the problem and a loff of ions however the frogs then uptake ions as they need them from not only the water but if they have access to a substrate that contains ions they can absorb the ions from the substrate through thier drinking patch...... 

Some comments,

Ed


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## psychedelicwonders (Oct 15, 2008)

Ed said:


> This is something that comes around all the time in various forums and articles. This is only a problem if the frogs cannot get out of the DI/RO water and even then the frogs are able to compensate for it as they can reabsorb calcium and other ions from the water through thier skin. It would divert some calories from other metabolic processes (which to some extent is not that big a problem since many frogs are obese) until the frog was able to get out of the water.
> 
> The water does not "leach" ions from the frog, instead the frogs have to spend energy pumping the excess water out of thier cells and body which can cause a loss of ions.
> Any water that has a osmotic pressure of less than the frog is going to move along the osmotic gradient causing the frog to spend energy to deal with the problem and a loff of ions however the frogs then uptake ions as they need them from not only the water but if they have access to a substrate that contains ions they can absorb the ions from the substrate through thier drinking patch......
> ...


Quite interesting.

But if all you use is RO/DI, then how would the frogs be able to obsorb ions from other sources of water in the tank?

And they can actually obsorb various elements out of the organics in the viv (moss, dirt, tree, leaves etc?) and add it to their own body chemistry?

Thats quite amazing if its true.


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## Ed (Sep 19, 2004)

psychedelicwonders said:


> Quite interesting.
> 
> But if all you use is RO/DI, then how would the frogs be able to obsorb ions from other sources of water in the tank?
> 
> ...



If you use a substrate that contains calcium and other ions, then the water in the tank (puddles for example) will contain those ions even if all you use is RO/DI water however most of the mixes used in the terraria do not contain significant levels of those ions (however, still not a problem as long as the frog can get out of the water and is provided with correct supplementation of food items). This is why a number of people have moved past the typical soilless mixes are are working with clay substrates. 

If the substrate is wet, anurans can absorb calcium and other ions dissolved in the moist substrate, they cannot absorb the ions unless the ions are dissolved in water and moist soil has water which dissolved the ions. For an example of calcium absorbtion see 
Daniel F. Stiffler, Sepehr Eskandari, Shireen Dejbakhsh; 1998; Cutaneous transport in Ca2+ in the frog Rana pipiens: Significance and specificity; Comparative Physiology and Biochemistry; 


Ed


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## FrogOly (Oct 5, 2007)

Ed, are you saying that with a calcium rich soil mixture and by using water with low,or no TDS, you can actually supplement your frog's calcium level? Any thoughts about mixing old (or new) herptivite into the soil as well. If this is true, could benefits include reducing SLS?


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## Ed (Sep 19, 2004)

It will depend on the soil mixture as different ions will react (for example calcium salts of humic acids are very insoluable) together and change thier ability to dissolve. Based on the literature, I think you can supplement calcium to the frogs but I don't think we understand it well enough to figure out a way for it to be a major source of calcium. This is one of the major ways calcium ends up in streams and puddles in the wild. 

I would not advocate mixing any multisupplements into the soils since thier are a lot of items in there that can support a major bacterial bloom (which are likely to consist of bacteria like Aeromonas which can be opportunisitically pathnogenic to the frogs). This is one of the ideas behind a number of us moving towards clay substrates (in addition to an apparent ability to support a higher invertebrate population). Check out the clay substrate threads as this will give you a better idea of what is involved. 

Have you read the article I wrote on SLS in Leaf Litter? If you are already well supplementing the adults with calcium and there is calcium in the developement water for the tadpoles, then I would not expect this to be a likely resolution as opposed to other nutritional possibilities (unless of course you are using water that is high in phosphate..and then the addition of calcium could easily correct the problem...) 

Ed


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