Farm pond- bales of hay to control algae? How is this done?

I have acquired land that includes a farm pond a bit over one acre in size. It has a lot of gr like plants growing from the bottom, and floating algae. I am going to get gr carp to put in there to help eat it up, but I have heard that you can throw in bales of hay to control algae growth. Do you just throw them into the middle? How many? How does this work, biologically? Thanks!