Why Does Surface Scum Suddenly Go Away?

[nry]

For a while I have had a film build-up on top of the water. I had it initially when I set the tank up last July but it went after ~4 months.

It started appearing again maybe 3-4 months ago, it was there yesterday, but tonight it has completely cleared - I have done nothing at all today, nothing this week since the 50% water change (EI) last Monday and dose fertilisers as normal. I am fairly sure it was there this morning aswell.

All very wierd, I am not complaining, it's just wierd that it didn't seem to gradually go but has gone 100% within a day!?

 

[Graeme Edwards]

When ever i have had the same surfice scum, ( the protine film on the water sufice ) . Usaly after a day or two of not feeding, it goes away, wich makes you think,( if its the protine scum ) that its there due to over feeding! It proberbly goes away quite quickly due to bacteria using as a food sorce.

 

[nry]

If nothing else I have fed the fish a bit more recently, my new harlequins seem to refer feeding later at night so I have been putting a small pinch in ~8pm and the normal feed for all fish at ~7am.