I need to tell you a story and everyone else who will listen.
Yes salt creeps. It will creep up out of your tank, up into your hood, down tubes and down wires. Your water evaporates. Evaporation can't carry salt-just h20, leaving behind salt crystals. The water keeps coming up the salt (kind of like a candle wick), evaporates some more and creates more salt crystals. So you get a trail of salt that absorbs water and you end up with kind of a siphon. (am I doing ok?)
I have had fire marshals come into my store to look at our fish hoods to figure out how it caused a fire. They have told me that many fires each year are caused by salt creep, getting into the light and joining the two, or four prongs and the salt which is wet, so it is conductive and lighting the flammable salt on fire in turn burning a whole house down. It was the owners fault most of the time because of not using the glass on the top of their tanks.
Okay so knowing this I know to be careful, right?.........nope
I have my QT tank in my room with a couple of fish in it. I don't pay much attention to it like I do my other tank. I came home from my job and smelled this electrical smell. My other half said that he was messing with electronics so it made sense and I went to bed. I woke up around 5:00am and I could of swore the smell was stronger. I did a check around my bedroom, I looked at my tank and thought since I just moved the tank there a couple weeks ago, I would of notice it creeping, it wasn't there long enough to have much.
So I decided to go back to sleep. Not even ten minutes later I heard a POP I opened my eyes just in time to see the whole corner of my room light up. The plug was shooting white flames from it and caught my baseboard and wall on fire. Crap...if I wasn't awake, or if it would have happend in my show tank, the whole place would have went up.
The creep went up a wire and started siphoning in the little dip in between the wires and water was getting into my plug thingy and then it crystallized. As soon as it joined the two prongs, it cause a huge electrical fire.
I would of felt like crap knowing better than that. All you need to do is keep the glass covers on top to protect your lights and make sure there is a drip knot or your wires are higher than your tank.
I have heard of people's wood floor being ruined, carpet, and rot iron stands collapsing due to creep. Salt is extremely corrosive. That's why in all care and how to books they all tell you to clean the creep when you do your maintenance.