What should be in the tds? (was Re: Dehumidifier water)

[Wright Huntley <jwwiii at pacbell_net>]

Stoecker,Michael,FRANKLIN PARK,NC&C wrote:
> Wright,
> You wrote:  "Tds between 50 and 125 seems ideal for most softer-water
> fishes, as long as all of it is not Ca and Mg salts."
> 
> Sodium salts?  I don't quite understand the second part of the sentence.

Good of you to point this out. It is important.

IMHO, good fish water has a great *many* salts in it. Need may vary a 
bit by species. Certainly, *some* sodium chloride is needed from 
somewhere -- fish blood is saline! Rainforest Aphyo eggs may not do at 
all well with lots of Ca or Mg in the water, but *Lamprichthys* can be 
the opposite. Just try to get some desert pupfish to breed without 
enough boron salts, for another example.

Ca and Mg are basically needed for most physiological processes, but Fe 
(iron for hemoglobin) Na and Cl are vital, too. This is one reason why 
pure RO or Distilled/deionized waters are so hard on living creatures if 
not modified by adding back at least a *little* mineral-rich tap water.

The total number of required trace minerals is debated, but no one 
doubts the need for them. Fish can get many of them from their food, but 
good water is an important starting place. That is what I meant by 
having more than just Ca and Mg salts in the water.

One can probably do about as well as the expensive salts sold at the 
LFS, for reconstituting RO or creating Rift-Lake water, by mixing up a 
bit of Table Salt*, Plaster-of-Paris, Epsom Salts, Baking Soda, and a 
good trace-element mix. The PoP provides Ca (CaSO4) and the ES gives Mg. 
KH can be fixed by the baking soda, but the trace elements are vital, 
too, and some are just not in food in adequate amounts, IMO.

Since they *are* trace elements, most are found in almost any water that 
is not dead soft -- often only ppb are needed. Iodides are one common 
deficiency in many inland waters, but using a little iodized table salt 
fixes that, easily.

Wright

___________________
*I prefer the kind of iodized table salt that uses sodium ferrocyanide 
to stop clogging and caking. It's also called "Yellow Prussiate of Soda" 
to use a middle-ages name that doesn't spook the chemically illiterate. 
Silica Gel (aka silicates) seem to produce an insoluble cloudy 
precipitate that irritates fish gills. That's probably what started the 
unfounded rumors that "iodide" was bad -- it is not. It is probably as 
essential for preventing fish thyroid disease as in stopping goiters in 
humans.

-- 
Wright Huntley -- 209 521-0557 -- 731 Loletta Ave, Modesto CA 95351

"The main political divide of our time is between those who trust
   the state and those who do not." -- Alberto Mingardi

                  http://www.sfbaka.net/


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