What of your tanks water currents, which water pumps and how many do you have in your tank, for dead water spots can do some strange things by allowing you to think its something other then what your problem really is. Your a deep tank for I too years ago kept a 110 gal tank, and in any tank system we need to make sure that no matter how much LR we have in the tank, you need to make sure that your no dead water spots. For when I was running a 130 gal tank, it had five water pumps for this tank was loaded with LR. only once during my years in this hobby did i ever see this in one of my tanks.
Buddy
