to pump or not to pump?

[Data]

I just bought a (none) pumping xenia.
what are the odds of a pumping one stopping to pump and a none pumping one starting to pump?
are they all pumping and not pumping when ever they "feel" like or do you have to buy a pumping one to make sure it will pump in your tank?

I know, lot's of pumping questions :D

[David P]

first, even when happy not all xenia pulse or pump. You must have the right spieces (quite probable you have the right stuff) Give it a little time to aclimate to your tank.