Copper anode Nickel anode Lead anode Anodes are basically what keeps the initial metal make-up in your bath at a usable level. They also serve to supply the voltage into the tank for electroplating to take place. What does this mean? Here is how it works. When you initially make up your electroplating bath you add something called metal salts to the water. These salts contain the specific metal you will be plating in that bath. As you electroplate the metal is moved out of the solution onto the part you are plating. If you do not replenish the supply of metal in the solution it will cease to plate. Big companies have to regulate how much metal is in the bath and the proper PH and specific gravity of each solution to keep plating consistent. On a hobby scale this is not needed. The metal is taken off of the anode in ion form and placed back in the bath during the electroplating process. The anode is connected to your POS + side of the power supply for plating. The metal is initially supplied in the following baths by the listed chemicals: Nickel plating bath contains Nickel sulfate and Nickel chloride. Copper plating bath contains Copper sulfate. Chrome plating bath contains Chromic acid.   Your Nickel bath will need pure nickel anodes (99.9% pure) otherwise you will get a white crud/sludge that will gunk up your tank. Wrap your nickel anodes with a porous cloth and secure the cloth with some stainless steel wire or rubber bands. The function of the cloth is to catch any anode sludge that may be forming on your anode so it does not fall into your tank and create plating problems later. Your copper bath will require copper anodes. These can be in the form of sheet, pipe, bar, or any other good grade of copper. Your chrome tank will use lead anodes. Lead you ask? I thought we were plating chrome? Yes. Chrome is a bit different as it only uses the anodes to supply current to the bath. Use lead, as they are most resistant to the chromic acid and wont leach into the bath. If you use steel, copper or any other type of metal it will deteriorate in time into the bath and pollute it. I have my lead anodes for the chrome bath hooked together with a stainless steel pipe for the high amps and ease of use. Note: The lead anodes used in the chromic acid tank will normally build up a yellowish brown lead peroxide film. Scrub this off with a scrubby pad (usually used for scrubbing dishes and pots) periodically so good electrical current can flow.If you keep getting bright yellow deposits your current is not high enough. The deposit should be more to the brown side. NOTE: Take your anodes out of the solution after you are done using them. If you leave them in the bath they will disintegrate in time and gunk up you bath.