making colloidal silver

[Frank bao]

I have been making it for a year now and i want to be able to change polarities at the silver electrodes about every three to five minutes or so.presently have a 30volt dc power supply going to a current limiting circuit that keeps the current under 3ma. It males a good CS but oneside wears down faster thanthe other and guess Im a little lazy to keep cleaning and switching my wires around etc... can you help me with a circuit that will change polarities at the frequency mentioned above? Thank you for your help...

[hapticz]

a simple 555 timer set as a 50/50 duty cycle flip flop at 3-5 minute (use a pot to adjust the time as needed) , that drives a relay with 2 pole double throw set of contacts should work.