A few days after cleaning my 5gal planted tank I noticed many little white things crawling around on the glass they were about the size of the peirod at the end of this sentence. Anyone know what these are?

plancia or something like that they are called. they are flatworms, I looked it up after I had similar issues. They are not harmful to the fish, but they are a sign of over feeding and a buildup of uneaten food in your gravel. The decay from this could cause isues with the fish but the little white things are harmless. I and they recomended that you vacume your gravel once a day for 7 days and be sure to be thourough. The little things will not have any thing to eat and die off.