Fitting underslung 40ltr water tank to Ford Transit Custom

The 2 biggest issues in small Campervans are normally Water and Electric capacity. Having limited storage space in pretty much all campervans we first considered installing a 25ltr water container under the sink, which is common in most small vans, but not wanting to lose the storage space, plus I felt 25ltr was not really enough for our needs (washing, showering, dog cleaning etc) I researched underslung water tanks and found a company selling them for Ford Transit Customs, their promotional video stated they will fit any van and the showed it installed on a transit custom.
The installation looked pretty simple, well that was a miss conception in our case, mainly due to working off some levelling ramps, which made it pretty tight for maneuverability.
Hopefully this video gives others more of a guide on where to/we located the tank and the fixing strap used and fixing points, as opposed to us actually installing the tank, as videoing whilst working in such a confined space was pretty much impossible.