Algae on Log

That is a beautiful Algae-anyone know what kind it is?

I dont know the alge, but those are trumpet snails. If they are within a month the tank will be covered with them. I had a 40 gallon with them.
It looked liked 1,000 of them.

i had some of that algae take over my 20gallon tank and realized it would only start from an area that saw direct sunlight thorugh a corner.. i started that tank over a few times before i gave up and went to a biger tank at a different location in the house and some one asked me at the lfs if it had any direct sunlight "which at the time i sad no" because i didnt notice that a 1" by 4" corner of the tank caught the morning sun...

Hard to tell, but looks like a Cladophora sp. to me.