SW>  Unfortunatly the position of the tank is in a bad place in front of a
 SW>  window, but not in total full view, rear of tank is fully blacked out
Hi Steve,
The location of your tank may be part of the problem.  Tanks located too 
close to a window can cause large temperature changes in the water during the 
course of the day.  This can stress out the fish and hurt their immune 
systems.  It sound like everything else you're doing is right.  If there's 
any way to do it, I'd suggest moving the tank.
Robby
--- Maximus 3.01
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