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Oily film surface

5505 Views 8 Replies 6 Participants Last post by  Nigel95
So I am having an oily film on the surface. Read a lot about it like use a skimmer, don't put hands in tank, more surface agitation, use an air stone etc. But my question is does the oily film matters? Is it bad as I don't mind it. Looks like my CO2 bubbles get "trapped" in it.
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Mm, it prevents gas exchange, which is pretty bad, especially during times when there is little oxygen production (i.e. at night). If you have a ton of plants and a ton of fish, then that oily film might cause the death of the fish due to hypoxia...but that's rare.

The oily film can also get very, very nasty, as it grows bacteria on it as well...

Overall though, you probably don't have a problem and can get away with removing it when you do water changes (just as a preventative) rather than every day.
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The oily film in aquariums is typically a biofilm, that is associations of bacteria, fungi, algae, polysaccharides, etc.

It may limit gas exchange, which as you mention can function both ways, help keep CO2 in, limit O2.

It will also reduce the light penetration as it is effectively a filter.

Looks bad

It increases the organics released in the water which might favor BBA.

Now, this last point is worth discussing more. The reason why you have surface biofilm is because you have enough food for bacteria in the water to start with. Of course if you have stagnant water you will get a little water surface biofilm but the (re) generation time is long and thus unlikely to be a problem in aquariums with fish and some pump. I noticed the biofilm becomes thick when there is an abundance of ammonium. Another more whitish biofilm is present when plenty of iron is present.

Thus, the biofilm tells you there is an abundance of bacteria nutrients in the aquarium. Removing the source will reduce the growth rate of the biofilm. As you mention increased surface turbulence, skimmers and fish that eat it (guppies, platies, mollies) are good ways to keep things in check.

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Does it form like a "skin"? How's your nitrogen readings?
Tank is still fairly young I assume.
Tank is young, water is about 4 weeks in. If I need to describe it it's a white/purple fog. Can't get it proper on my camera only the human eye will see it. Idk about a skin yes there is a layer. I don't have a personal test kit. Seller told me water parameters fluctuate a lot in a nano and testing isn't that reliable.
Parameters do fluctuate more in smaller aquariums and that's all the more reason to have a test kit. Just my opinion

Dan
Tank is young, water is about 4 weeks in. If I need to describe it it's a white/purple fog. Can't get it proper on my camera only the human eye will see it. Idk about a skin yes there is a layer. I don't have a personal test kit. Seller told me water parameters fluctuate a lot in a nano and testing isn't that reliable.
I think I had something similar in my tank after a few weeks. I think its just the "biofilm" you get on new tank with a nutrient rich substrate. All my new tanks have had it but on the tank with CO2 it seemed like it was really pushed to the surface by undissolved CO2. It got really thick for a few days. A couple of water changes and time, it cleared.

*I would definitely test.
What additives are you using (ex. Excel, Stability, Parguard, etc)?
What additives are you using (ex. Excel, Stability, Parguard, etc)?
VIMI all in one fertiliser
Added VIMI stimulator only once since last water change. Kinda scared to use it anymore because of the fish and shrimps in the tank.
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