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Re: Daphnia in hard water
Hello Douglas,
You seem to have "liquid rock" for water! My water is about 400 ppm
hardness -- slightly softer, but not by much -- and several species of
Daphnids live in it OK.
The trick is to VERY SLOWLY aclimate them to your water. Daphnia are
sensitive critters -- that is why they are used for water quality
testing -- and any rapid change in water parameters will likely result
in stress and eventual death.
I would recommend that you, literally, add your water to the starter
culture drop-by-drop (through an air line with a valve or a knot) at
least the first 50% of the fresh water. The slower you add the water,
the less stress on the Daphnia, the more likely the successful survival.
In similar situations I usually set up a drip overnight, so that I loose
no time fiddling with adding the new water and the critters (crustaceans
or fish) have an easy time getting used to the new water.
Hope it works out fine for you!
Best,
George
>
> Date: Tue, 13 Feb 2001 11:25:07 -0600
> From: Douglas Guynn <dguynn at nwol_net>
> Subject: Water quality
>
> Below is an analysis of water from the city where I live;
>
> General
> pH 7.6
> P. Alkalinity as CaCO3 0 mg/l
> Tot. Alka. As CaCO3 121 mg/l
> Total Hardness as CaCO3 571 mg/l
> Dissolved solids 1385 mg/l
> Bicarbonate 148 mg/l
> Carbonate 0 mg/l
> Dil Conduct 2814 (umhos/cm)
> Calcium 126 mg/l
> Chloride 469 mg/l
> Flouride 0.4 mg/l
> Magnesium 62 mg/l
> Total Nitrate 0.21 mg/l
> Sodium 263 mg/l
> Sulfate 380 mg/l
>
> Metals
> Barium 0.199 mg/l
> Chromium < 0.01 mg/l
> Copper < 0.006 mg/l
> Iron < 0.013 mg/l
> Lead < 0.001 mg/l
> Manganese 0.013 mg/l
> Nickel < 0.02 mg/l
> Selenium 0.0156 mg/l
> Silver < 0.01 mg/l
> Sodium 236 mg/l
> Zinc <0.02 mg/l
>
> Is this water suitable for raising D. magna? If not, could it be mixed with
> RO water to achieve a tolerable dilution, or should I use RO water and one
> of the mineral addititves like RO Right?
>
> Thoughts?
>
> Douglas Guynn
>
> In west Texas, where ANY amount of rain is appreciated.
>