Ethanol fuel fix?

I have a few gallons of ethanol fuel in my tank - I have been told it will harm the fuel system...is there a way to counter the effects without raining the tank? Any additive I can use plus filling the rest of the tank with non-ethanol fuel? Any thoughts? Thanks!

Yes. Lucas makes a fine ethanol additive. This size treats up to 25 gallons.

Lucas Safeguard Ethanol Fuel Conditioner 10670