That video needs to be pulled from the internet all together. When I installed mine, I called Malibu to ask them. BFI had no clue at all (sorry BFI, but if you make a product, you should know everything about it). The guy in the video takes the hoses from the inside, and should have taken them from the outside (farthest from the engine), not to mention the fact that he doesn't use the proper fittings.
The hose that goes under the floorboard is the drain (should stay low and at a constant down-slope) , and the short hose that comes from the anti-siphon loop is your fill. The vent hole should be blocked off on the sac. The fat sac fills first and gravity feeds into the hard tank. When draining, the hard tank will drain faster than the sac can feed into it. I'll drain it until it spits air, and turn off the drain and let the sacs finish feeding into the tanks. Then drain it again once the sacs are emptied. The front sac is a standalone with it's own switch. The hoses are pretty much self-explanatory. Front is the vent, the fill will be the one that you can hear the loudest noise through (or spits water if you're floating) when the pump is on, and the other is the drain (connects at the bottom, with the hose as short and low as possible).
FYI, the 400lb sacs that are (Axis specific) are unnecessary. They make the same size sac with the unneeded drain in a different location, but no Axis logo
Can be bought in a set saving you $180
over the Axis sacs. Just get the proper fittings. And if you're wondering if the 750lb sacs fit... they do. AND, they also plug right into the PnP system.
