Yep it's leaking.  So slowly I hardly noticed.  The ATO is keeping up with it (I had to increase the ATO pump timer by a minute last week and this explains why) but I guess I should start adding salt to keep the salinity up.  
I can't pinpoint exactly where the leak is yet (I think it's on the bottom) but the salt creep gave it away.  I'm calling around today to see if I can find a replacement locally.  It's a metric tank so it's not easy to find (100 x 40 x 50 cm).  I'm also getting quotes to get it shipped in for me.  
http://www.hagen.com/canada/english/...01029740010101
It will all come down to price if I plan to continue.  It's not the way I want to go out but sometimes you just don't have a choice.
