We have a seperate filter for the unit. It draws a very small amount of power. Defender had the best price when we bought it a couple of years ago. It runs in the background almost year around. GET ONE if you are concerned. There are more expensive systems (like Filter Boss); however, for your boat, and the room you have available and the cost, I am not sure that would make sense.
I had a bit of crud when I didn't use much fuel one season and didn't keep my inflatables full. We have four fuel tanks. Port and starboard hard tanks, with each of them having an inflatable tank above them. When the hard tank gets drawn down, we can drain the infatable "above it" into the hard tank. So if we aren't using the engine or generator much, then I get concerned with fuel quality in the tank. The inflatables don't have clean-outs. The depend on flushing.
As for determining if you have crud in the bottom of the tank...
I think that if you have noticable crud in your prefilter's bowl or the fuel looks dirty, then if you continue to see those symptoms after using fuel, I beieve that either
- you are refilling the fuel from a bad source; or
- you have a problem in the tank.
The first step is usually to polish the fuel. I would think that would make sense unless there is any water or serious crud.
If the issues appear more serious, my approach would be: If you have a clean-out in your tank, then I would open it up and visually inspect the tank. If you see a clean bottom and sides through clean fuel, then clean it.