I at the moment do not have a freshwater tank, I took a break from keeping a tank at least for the time being as I did not find that I had the time for it at the moment.
Many others will more than likely have a freshwater tank though and it could either be a new tank that you have just set up or one that you have had for a while that you are maintaining.
The current freshwater tank you have at the moment, how long have you had it for?