Hi all,
do hastatus prefer strong or weak current?
I think they don't like really strong currents, my tank has had both strong and "normal" flow whilst the
hastatus have been in there. Originally I had a Eheim 2213, a Maxijet 900 (with out-put running a long the bottom of the tank) and a Eheim Aquaball (with venturi). This gave both a lot of surface turbulence and fairly fast flow lower in the tank. One thing I found fairly quickly was that Marbled Hatches and strong surface turbulence is a bad mix.
The
Corydoras hastatus were initially very bottom orientated and never left the lower 2" of the tank. I now think this was to do with the "ground effect" of the caves, pebbles etc breaking up the linear flow and creating calmer areas where they were more comfortable. Having said that they grew and didn't seem noticeably stressed.
Since then I've put a much larger sponge onto the Maxijet, swapped the Eheim 2213 for an Eheim 2211 with spraybar, and taken the Aquaball out all together. I've also added a lot more structure. The flow is now such that the
Limnobium and
Salvinia are not so tightly clustered in a corner, and the submerged plants are gently swaying, rather than being stretched out in the current. The
Corydoras are still mainly bottom orientated, but they do occasionally shoal in mid-water, and travel both over and through the bog wood and plants quite comfortably, rather than being entirely bottom orientated.
cheers Darrel