Film on water...

[juliethegr8t]

Tonight I just got a different perspective on my fish tank (it was dark and I turned on a light above while the cover was open), and I could see a sort of oily film on the top of the water. Now I'm worried! This may have been there for a long time, I've never looked at the water that way before, but I am not sure. Anyways, should I be worried, should I take action, what should I do? The film isn't colored like oil, and doesn't look thick, it's just there. My pH is 7.4, my ammonia is 0, and as most of you know - my nitrites are still high. However, the fish are all doing splendid and have been for a little bit now. I did add some of the "Cycle" product today, could that be it? And since my tank is still in it's first cycle, I don't know if I should do a water change? The last time I did one was Wednesday (20%). Thanks for any help!

 

[Interfire]

You know I have the same problem, but I have noticed that when you increase surface agitation it seems to get better. Maybe someone will shed some light on this as I was wondering about this as well.

 

[teknikz]

it could just be oul/grease from ur food......i get like an 'oil slick' on my water when i add food to my tank......

it could be stopping air getting into ur water so if its possible......try change the direction of ur water flow from ur pump to the surface.....that will stir the surface up and should break the film thats on top.....if u have an air pump and airstone this shoulkd do it too

Tek

 

[devinf]

I get the same thing sometimes but I do not believe there is much to worry about. it could be caused by the oils on your skin, if the tank is near the kitchen, high protein flake foods can also cause it....

Unless you see some adverse affect on your fish or in your water quality, don't worry... to clean it up increase the surface agitation or you can take a paper towel and drag it across the top of the tank.

Devin

 

[Dragonslair]

The "oil" on the water surface is normal as long as it is light and barely noticeable. It is known as protein or scum as I used to call it. There are units called protein skimmers, these are designed primarily for marines, but can be useful if you are concerned. A finer agitation of air bubbles or an air bubble curtain coupled with a greater surface agitation using a power head will cure this problem. If you have "toys" that release bubbles into the water, this would be insufficient to do the job. Remember fish can't breathe the bubbles, if want to know why, just ask later.

 

[Wasserpest]

To get rid of surface scum IMO there are three ways...

1) Clean water/reduced bioload/better filtration

2) Surface agitation

3) Fishies, like Mollies or Pearl Gouramies, eating that stuff

It's not dangerous per se, just looks nasty, but it will reduce gas exchange which could get problematic for your fishies.