Re: What metal solute turns water a tea like color?

Since the metal rod responds to a magnet, it is probably either Fe, Ni, or 
Co, or a Stainless steel alloy, or [very unlikely] something like Alnico.

It is most probably Fe or some Fe alloy.  Aluminum Nitrate solutions are 
slightly acidic, and will attack [corrode] some metals.

The bubbles are probably hydrogen, and the "tea" color is probably due to 
dissolved iron in solution as ferric nitrate.

A metal in contact with a solution of its own salts [ say, Al in Al 
nitrate] will generate a potential that can be predicted from the EMF 
tables, etc. But a metal in contact with a salt of another metal forms a 
potential which is very hard to predict.  Also, when you attach the steel 
wool, you add a third metal to the situation which makes things even 
more complex. Also, the steel wool may now be reacting with the unknown 
metal rod, generating a different potential. 

I suggest that you test the solution for the presence of Fe. I do not know 
what chemicals you have available in your laboratory for testing. 

One easy one is to prepare a dilute [say, 1-10 %] solution of Potassium 
ferrocyanide.  To a few drops of this add a few drops of the colored 
solution. An intense blue-black color ["Prussian Blue"] will indicate Iron. 
 Try this on a known Iron salt first.