Water and roof run off marks

I like Sam's club degreaser for this. Works very well. I think there is some type of petroleum based "runoff" that comes off the roof mixed with the minerals from the rain. I think the degreaser "destroys" the petroleum and thus makes the mineral removal easier. Simple green would work for this too.

I can't believe no one has mentioned a degreaser like Simple Green. There are cheaper versions of the degreasers. I think Walmart sells a degreaser like Simple purple or something like that. These degreasers also work great for restoring your rubber roof and lap sealant back to white. It works great for removing the water marks from the run off. Spray it on straight from the bottle. Do not dilute it into a wash bucket. Just scrub it with whatever you wash the motor home with. It comes right off with virtually no trouble at all.

Even simpler...Mr. Clean Magic Eraser. But first, you gotta clean the roof and wax it to keep the oxidized paint from running down when it rains or from dew or A/C condensation.

For water spots on Windows just use a wet dryer sheet. Rinse after and you'll be spotless.

If the mark is black, it can be removed easily with bleach based tub and tile cleaner from the dollar store, or the more expensive black streak remover from any camper store or walmart.

I have had success using 0000 steel wool to clean the window and remove the water spots. Gentle rubbing usually removes the spots. After using the steel wool, wipe off the dust and then coat with RainX. The RainX will dry quickly to a slight haze. Use a clean cloth to buff off the haze and have wonderfully clean windows that repel water.

I got a glass cleaner cream at a box store or auto store Because of roof run off and where we lived they had extremely hard well water which always left windows spotted after washing the rig. I don't have the name of product because the label came off. Also my Rexhall has a fiberglass roof which keeping it waxed has taken care of the roof run off stains

If you want to get rid of water stains on glass, use a mild mixture of liquid automatic dish washing liquid and water, and spray it on and wipe it off like you'd clean any window. Dishwasher liquid is designed to remove water spots. You can also use a solution of the dishwasher rinse aid too. This also works.