The plant is 18" away from a recessed north-facing window with no direct sunlight. The heat, of course, changes through the year and I try to move it further away from the window as it gets colder (no hotter than 25C in summer and -2C in winter) and position it about 6' away of this unheated bedroom. As of today, it is 20.7C but will drop as I need fresh air in the room to sleep.
I have kept it quite well watered while allowing a 7-10 day period to dry out and then dunk the sizeable pot (with lower side vent hole) in a bucket of fertilized water (medium strength 20-20-20) that has stood overnight (to de-chlorinate) and ensure the vent hole is entirely emptied of water before putting it back. It has never been so water starved that it drooped and I have never had yellow leaves.
I have even begun to mist it in the last 2 months in the morning every 1-2 days (I have to move it each time) hoping this would have some benefit as I saw this referenced on a website and was not doing it.
I am still getting the tips of the leaves turning brown and dry. After a certain point, I have cut some off gradually because they are pi**ing me off. This, of course,results in less and less leaves with no burst of new growth.
It also has never 'flowered' and was much more robust when it was given to me over 4 years ago (without any brown tips). I have not re-potted as it is getting smaller, not bigger.
After all this puttering about and researching, I find it hard to believe that I am doing something wrong. I want a divorce but I hate being beaten by a plant that is supposed to be so easy to care for. Help before it goes over my 4th floor balcony!