I have 2900D, but as far as I know the back half of the floor plan is nearly identical. (slide sizes vary because of different brands used in different years).
The fresh water tank and the water pump are under the head end of the queen bed. After lifting the mattress off you'll find screws holding the top plywood in place. Under the plywood you'll find the water pump near the outer wall and the water tank (the heaviest thing) furthest from the wall.
I've previously posted a photo of what it looks like under the bed in this thread [size=78%]
https://forum.phoenixusarv.com/index.php?topic=5122.msg45528#msg45528[/size]
Note, this photo also shows my 2 gallon pressure tank and the insulation I added in that compartment. Your rig will look different.
Sorry.. That is about as much as I can help, but questions are welcome. Maybe a 2910D forum member will chime in.
As for the inline water filter question.. That would be a nice option. I've considered installing one and the only place I can find to put it would be on the bathroom wal near where the city water inlet is. I would want it somewhere easy to change the filters. It just hasn't bubbled up to the top of my to do list yet. So, basically I don't know if your rig has one.
