swiming exercise

[Josesilva]

Hi i have a external filter and the end that`s in the tank is under the water level. Im just wondering why my fish (neon cardinal) are most of the time swiming in front of the water flow. Are they in need of something or do they do this for the exercise...? thanks for the help.

water test: (hagen)

GH--------200
KH----------60
PH---------7.0
No2--------0.1
No3---------10
Temp-----26ºc

[ChilDawg]

They might like a little stronger current in their tank, or they might like a reduced one and have just been sucked into the area by the powerful filtration. I am guessing, though, since cardinals and neons are so streamlined, that they would like a little more current throughout the tank.