CO2 tank residue

[Averus]

I was wondering if anyone have some advice for me.  I received a few months back a co2 kit that uses Baking Soda and Citric Acid to make the co2.  I will eventually get pressurized co2 set up, but this is what I have now.

So the system is working fine since I got it in February, but I end up with a bunch of residue in the co2 tank from the chemical reaction.  Anyone know any easy way to remove it?  It is really solidified in it, so just washing it out is not a good option.

[Zenzo]

You can remove it and soak it in vinegar and hot water. That should loosen up the buildup and allow you to clean it. Just make sure you rinse it well before returning it to the tank. 

[Averus]

I do have hard water, but fortunately I have gallons of distilled water on hand.  I also grow carnivorous plants, and need it to water them, as the tap water would fry their roots.