How about those dreadful sea water aquarium constraints?
In the beginning we had been extremely pessimistic with respect to
the survival prognosis for our maritime tardigrades within the micro aquaria.
As probably all of you will know, sea water aquaria, small aquaria and moreover micro aquaria
are generally considered as complicated, inadequate and hopelessly fault-prone.
And you don't need much of imagination to understand the big difference: an
endless ocean on one hand, a cupful of water on the other -
fresh air, wind, waves and currents in the oceans, little exchange whatsoever in
a micro aquarium.
Furthermore those sea water aquaria are subject to lots of intellectual discussions
based on what appears to be a terrifyingly complicated, physico-chemical background.
And we had heard rumours that all those impressive "Sea-life" enterprises
were in fact dreadfully dependent on the profound knowledge of their local sea water specialists.
So, when taking a water sample with Echiniscoides sigismundi
at Lisbon harbour a few years ago we had been eager to note the water temperature and
had poured the sample into a thermos bottle at once. We had been convinced that
the life expectancy for tardigrades within our small containers might possibly
reach only a few days or weeks at best. In order to better care for the
tardigrades we planned to control and monitor the salt content
of the sea water as well. We thought that similar to a surgeon with his stethoscope
we were badly in need for a salt measurement device, a refractometer.
Well, today, thanks to Ebay, this was not a great problem and here it is: