What a question ! I don't believe the aeration could cause the LMB to have a second spawn. But by changing the temps. it sure could slow down the spawn and make it a prolonged one. Here is some info on LMB spawning dates. I have "heard" (pure speculation) that in some unusual circumstances LMB can spawn in spring and again in early fall.

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=7;t=000305;p=1#000000