New Tank Setup

[gangeox]

Ok, so i got the tank and its full of water and sand a and bits of wood at the moment and just letting things settle, can someone tell me how do i know if the filter/pump is working (its a rio 180) is there any tests i can do? and also the there is a lot of 'scum' on the surface how can i remove it?
Think thats it for the mo'

 

[2day]

I wouldn't have a clue for the filter.... Just look at it and see if it is sucking up water and debri. As for the scum, just pick it up with a fish net and throw it out, and just rinse the net out properly....