White 'powder' on water surface - any ideas?

[jmeunier]

I've got a 2-year old 150G FW SA cichlid tank that has what looks like white powder specs floating on the water surface. These just appeared a day or two ago, and are very dense. If you put your finger in the water, they'll adhere to your hand.

Any ideas on what this is? Should I be concerned? How do I get rid of it?

Thanks

 

[QTOFFER]

Is the tank covered or could something have fallen into it? Have you added any new rocks, substrate, or decorations recently?

 

[Zagz]

Perhaps some small kind of bug from outside? Similar to afids?

 

[Jarred Darque]

Are your fish doin lines in the tank?