Bio film is usually sign of poor plant health, though can occur when fresh plants are first placed in water.
Rather than sort the film via outflows/airpumps/absorbing by kitchen towel etc you need to sort the cause of the film rather than the symptom. My bet would be poor CO2 distribution for your light level.
I suffered bio film when I first started CO2 and EI, but fixed by adding a powerhead to distribute CO2 better and film stopped. Oh air pump at night helps as well.