Adding non ethanol fuel to ethanol fuel

[Longrange1971]

Hello all,
I have a 167 gallon tank. Before I launched her for the season I put regular fuel in it (ethanol). The marina I'm at only has marine fuel. (non ethanol). My plan was to wait until it was down to about a 1/4 tank and then fill with marine fuel. Has anyone ever had a problem with adding non ethanol fuel to ethanol fuel.
Thanks

[artdf175]

have not heard of any problems adding non ethanol to the ethanol
running down to a minimal amount of ethanol would be a good idea if you don't have any trips that would compromise your ability to get back to the dock
would make sure you add SeaFoam or comparable to the ethanol fuel
I have mixed the two fuel types in the past, until I was able to find a good source of non-ethanol, with no problems.
I have not experienced problems with moisture, but do monitor your water/fuel separator filter periodically
Art

[Longrange1971]

Thank you for the reply, moisture was my concern. I understand that ethanol fuel will hold a certain amount of moisture, but non ethanol will not. I was concerned with separation issues. I have twin motors and fuel water separators on both. Thanks again

[Harper]

Ethanol-laced gasoline does not contain water, but does absorb it from the atmosphere. The ethanol itself is hygroscopic. The water is held in suspension in the ethanol, since they do mix, unlike gasoline and water. What happens is, once the water content in the ethanol reaches a saturation level, the water separates (phase separation) and this is where the trouble starts. If you haven't already gotten into a phase separation condition in your tank,, the addition of pure gasoline will not cause you any problems. If you already have phase separation, the addition of pure gas without first ridding the tank of the separated water, will not help or cure the problem.

[Longrange1971]

That is great to know. I do not have a fuel problem right now and just wanted to make sure I wasn't going to cause one.
Thanks