Does anyone know how well the diesel will fare in long term storage in this aluminum tank? I know that once I get 90 gallons in there, I need to add Pri-D. I'm wondering if I need to have any elaborate filtration or fuel water separator setup between the aux tank and the generator. From what I understand, if I keep it clean and keep water out of it, it will last a long time. I have used 20-year old diesel recently in an 802 and it chugged along without a problem...
It's not so much keeping water out (which, yes, you will need to do but...), diesel is hygroscopic (absorbs water from air), and will release water when the conditions are right. This happens when there is enough space in your tank for cold surfaces inside the top of your tank meeting ambient air (since you need a vent in the tank to allow air to flow in once fuel flows out) - this air+cold surface results in condensation forming on the walls of the tank and then water will enter the fuel. This mixture really supports algae, and the water and dying algae will settle in the bottom of your tank as a sludge. Since your pickup is low in the tank, this sludge will get sucked out first, and fill up your fuel filter membrane. This is why I advocated for a fuel polishing system.
...I know installing yet another fuel water separator could be overkill but I'd rather be safe than sorry and have went this far to do everything right...
The above is why I suggested a fuel polishing system - a water separating fuel filter with a very large filter (think highway truck, Quarry truck, or large marine filter). The larger the filter the more algae the polisher can take out of the fuel tank, and if this is run before the generator during weekly exercise, you can spare your generator's filter from the harder work
. You can use a cheap hand pump if you don't want to buy an expensive electric pump (and less to break when it's critical).
...Also, I'm looking for fuel line suggestions for plumbing in the tank. Some folks have said use the aux fuel hose that came with the generator. I don't think I need a 20' hose but will use it if it is the best one for the job. I'm looking for something that won't rot and degrade over time.
Any highway truck fuel line should work since they are usually UV stable and resistant to road chemicals and abuse, it would be great if you could use the fitting from the aux input - you might look at at a local hydraulic hose shop and ask what they'd recommend - they should be able to build you a custom hose set relatively cheap.