Aeration and CL drop

Yesterday afternoon I noticed a very slight yellowish tint on my pool walls so brushed them down and saw a slight yellow-brown cloud go into the water. Since I just got through with my battle with algae, I went into "over-kill" and shocked back up to 30ppm last night, just to be sure to kill anything that was trying to grow again. I also have been aerating to get my TA in line and I left the aeration going all night. This morning my CL tested 12ppm. This is a huge overnight drop with crystal clear water and I'm wondering if the aeration had something to do with it?

Also, my niece just called and wants to bring her children (ages 1 and 3) over to swim today. Is it safe for children this young to swim in water with a CL level of 10-12ppm? (I am adding some fill water right now, so the CL level will be diluted a little bit by time they come.)

Thanks again!