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Re: water analysis

On Sat, 15 Jan 2000, Bob Olesen wrote:
> I am in the planing stages of an aquarium and here is an analysis of the 
> local tap water:
> total hardness:     75.0 mg/L
> total chlorine:        3.0 mg/L
> color:                   7-10 units
> turbidity               0.15 NTU's
> pH                        9.0 - 9.3 !!!!!
> total alk.                24.0 mg/L

Actually, the only thing I see wrong with this is that the alkalinity (24
mg/l) is low.  That's 1.3 degrees KH.  You may want to increase that.  
Total hardness (75 mg/l) is about 4 degrees GH, which is fine for plants
and good for most fish as well.

The high pH probably means that your water has been treated with some bulk
softening process like lime softening.  Those processes remove all the
dissolved CO2, raise the pH, and precipitate much of the hardness as a
mineral sludge.  The pH will probably drop to 8 or less when the water is
aerated, and in a normal aquarium the pH should be near 7.

If you find the color annoying you can probably use activated carbon to
remove it.  You will probably also want to treat for the chlorine.

You might check the sodium content of the water.  It probably won't be a
problem unless it's over 200 mg/l.  This is a rare problem in potable
water, but it happens.  If it is that high, then it can cause deficiencies
in potassium, calcium and maybe even magnesium.

Roger Miller