Electrolysis of a salt solution, after about 2 minutes all of this green "scum" started to appear. What is it?

Could mean and I'm only guessing here, that you might have positive(+)where the negative(-)should be. Or it's possesed by the devil and puking green shit on you to show that its pissed and evil as Satan himself !



If anybody knows this answer I will be shocked!

What type of Anode/Cathode are you using?

Ha, yea - not the most expensive set-up. Ive got a 12V battery charger connected to two nails which are in the solution.

maybe it's chlorine?

It could be iron (II) hydroxide. Add a bit of H2O2 to the scum. Does it turn red/brown? If so, it's probably an iron (II) compound of some sort, which is to be expected when you're using a steel anode.

kman, chlorine (Cl2) is a gas at STP.

I want to agree with Gray, prehaps you might consider using something a little less reactive as your anode, graphite comes to mind.

mnm is correct.