# Bubbles appeared on water surface



## @thepuzzlemonkey (Nov 5, 2014)

This seemed to appear overnight, groups (or pockets) of bubbles formed on water surface.



Also, a kind of milky/oily film can be seen on top of water, nothing has changed in terms of setup.
The fish seem ok and my test kit shows water is ok, so whats going on?


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## Marshall (Jul 8, 2013)

normal when there are plants in the tank, it's caused by the organics in the water,

a little surface agitation normally breaks it up, plus it will help with oxygen exchange.

What filter are you using? if it's a HOB, try lowering the water level just a little to create some waves, if its a canister, try aiming the return towards the surface


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## @thepuzzlemonkey (Nov 5, 2014)

It's an internal filter, a Juwel Super Bio. I can adjust the output nozzle to aim for surface. 
Although I had been advised not to disturb surface in planted setup as lets co2 escape??? Confused.....


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## coralbandit (Jul 29, 2012)

If you don't inject co2 ,then air bubbles or surface agitation will introduce as much co2 as it allows to escape.
Without adding co2 ,the aquarium will want to find balance(equilibrium) with outside envirioment(our air which does contain enough co2 for the plants on the land!).


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## Gizmo (Dec 6, 2010)

It's caused by excess proteins forming a scum on the surface. As stated, agitate the surface more and should solve the problem.

You can also drape a dry paper towel over the surface of the water to absorb the scum, and then discard the towel or wring it out over your house plants.


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## chenowethpm (Jan 8, 2014)

If the "oily" surface really bothers you, you could get a surface skimmer. I ran one until I broke it cleaning it. It was made by toms.


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