Hello everyone! Haven't posted for a while, since our pool has been running "Trouble Free" for a few years. Approaching 7 years on our original equipment, so I was looking at picking up a replacement salt cell for the inevitable failure. Can I use an IC40 replacement cell in my system? Cost is about $100 more than the current IC20 cell. I figure I'd be ahead of the game since it should last a bit longer than the "20". Also, does anyone know if they are the same size--i.e. is it a direct drop-in replacement? Any help would be much appreciated.