odd surface film

[Little Einstein]

hi. I am setting up a 135 gallon tank. it is fresh water. i woke up this morning to find the surface of the water covered with a semi-solid layer that reminded me of bacon grease. i have no idea what this is and where it came from. is it toxic to fish? how do i get rid of it?
here is a list of things added to the tank:
water
tetra aqua safe
safe start
sand (black Tahitian moon sand)
rocks
some ph down
could it be one of these things?

 

[Spiritofthesoul]

Its just the organic film, you can deal with it by adding a surface skimmer to your filter inlet or just increase the amount of surface agitation

 

[Little Einstein]

thanks for the reply. i poimted my filter outlet up and my water jet towards the surface. it seems to help but what is the organic film made of?

 

[lipadj46]

did you rinse your sand? My guess would be from the sand, also why are you using pH down? adding buffers like that is almost always asking for trouble.

 

[Little Einstein]

the sand said that there was no need to rinse. it came in a wet package. the ph down is because my tank that is running has a very low ph right now and im trying to balance the two so i can transfer the fish.

 

[Latimeria]

What is the pH difference between the two tanks, and what fish are they?

 

[lipadj46]

are there fish in the tank?

 

[Spiritofthesoul]

http://freshaquarium.about.com/od/problemsolving/a/oilslick.htm

 

[Cecropia]

happens to any tank with no surface aggitation. Aggitate that mess!

 

[JK47]

What do you feed? Not all surface film is caused from lack of surface aggitation. (trust me) some are caused by simply feeding a pellet that is too large for the fish consuming it.