Are these Diatoms growing on the side of my tank??

[freyabelly]

I have had my tank (freshwater 30 gallon) set up now for about 6 months now. I keep getting this bloom of what I think might be diatoms, but am not quite sure. They look like round white balls that stick to the side of the tank and sway in the current. I bought some Otto fish to remove them, but they continue to grow.
Can anyone identify what these are and how to get rid of them??

Thanks!!

Here are the 2 images I took of the tank...
http://i22.photobucket.com/albums/b313/freyabelly/IMG_0053.jpg


http://i22.photobucket.com/albums/b313/freyabelly/IMG_0059.jpg

 

[Newman]

usually you can just detach them yourself with a scrubber of mag-float. i have no clue what they are. might be some sort of algae or debris collecting on the glass...

 

[freyabelly]

Thanks Newman for the advice.
I spent some time last night scrubbing down the sides of the tank. Those buggers were had to get off...There is no trace of them anymore.
Perhaps they are underwater dustbunnies!