720D Rust in Fuel Tank

I just realized my 720D I primarily used to cut hay (pulling New Holland 489) has been making rust soup in the fuel tank. The first filter was really bad the second wasn't as bad... The tractor has never had the power it should and last summer it was really falling on its face (naturally starving for fuel). Had to go back to the 60 to get the job done. I have a new tank that is very clean and I'm going to use Eastwood Tank Sealer to hopefully prevent rust in the future. I have a few questions here. I'm told the new Diesel fuels are corrosive and if you leave the fuel in the tank over the winter your asking for trouble... any truth to this? If that's the case should I look at using this tank sealer on the 2 filter bowls?

But my most concern is with all the rust what should I do further down the line with the pump and injectors. I am clueless when it comes to these parts. Ive seen others ask what PSI the pump is producing but would have no idea how to test that. Like I said the tractor has never had the power it should but is that an injector problem anyways. I can't find the spark plugs on the tractor to test the compression to see if that a problem. I would like to find a few things to check on my own before I send the tractor or parts off to get sticker shock.

Clean, dry diesel fuel shouldn't "corrode" a fuel tank.

I would install the clean tank without coating the inside, then change the filters and check the transfer pump pressure under load before considering tearing into anything else.

Procedure and "specs" are in the shop manual (which I don't have at hand tonight).

If the spare tank is clean and not rusted there should be no need to cote the inside,

Use clean, dry fuel, and some diesel fuel conditioner that deals with water in fuel from time to time, as well as an occasional dose of biocide, as needed.

I'm wondering if it is algae and not rust.

I think your probably right and there was some algae in the tank as well but there is definitely flakes of rust that came out of that tank as well. The algae looks more like a black slime. Just in the last year I've notice the fuel cap became very rusty. Thats what started me thinking the fuel was causing corrosion.

Look at the thread on the Ford forum about Colin's Ford 971D.