Foily / Oily surface scum

[jordzcov]

Hi,

Im currently battling with an oil-like surface scum. I have started dipping a cup just below the surface during each water change to try and remove as much of it (without collecting too much water) as I can, but it seems to return within a day or two. Ive also now tried laying paper towels on the surface for a few seconds in the hope this will absorb it, but havent done this long enough to notice the results. The layer can become very prominent in just a a few days and I have no idea how to combat it.



I have tried limiting the food intake ( fish have always only been fed once a day, but have begun giving a smaller amount) but this also hasn’t helped.
​

 

[Andy Sager]

Hi,

Im currently battling with an oil-like surface scum. I have started dipping a cup just below the surface during each water change to try and remove as much of it (without collecting too much water) as I can, but it seems to return within a day or two. Ive also now tried laying paper towels on the surface for a few seconds in the hope this will absorb it, but havent done this long enough to notice the results. The layer can become very prominent in just a a few days and I have no idea how to combat it.



I have tried limiting the food intake ( fish have always only been fed once a day, but have begun giving a smaller amount) but this also hasn’t helped.
​

What kind of food are you feeding and did you add anything new to the tank (i.e. decoration, rocks, wood, etc) before you started having this problem?

 

[Colin_T]

Do you have any aeration/ surface turbulence in the aquarium?

Do you wipe the inside of the glass around the surface when you clean the tank?

Have you started using a plant fertiliser or medicated the tank recently?

Do you have anything (hand sanitiser, cream, grease, oil, etc) on your skin when you work in the tank or feed the fish?

Does anyone paint, smoke or use any perfume, deodorant, etc, in the room with the fish tank?

Have you got buckets and hoses specifically for the fish tank?

 

[jordzcov]

Answered below

Do you have any aeration/ surface turbulence in the aquarium?

Do you wipe the inside of the glass around the surface when you clean the tank?
- yes, I usually give the inside of the glass a wipe down when I notice build up, and one a month give it all a full wipe e.g. taking the pumps out to wipe behind them etc.


Have you started using a plant fertiliser or medicated the tank recently?
- I haven't added anything different to what I've always used, which is a daily plant feeder. In this case one from JBL.


Do you have anything (hand sanitiser, cream, grease, oil, etc) on your skin when you work in the tank or feed the fish?
- not that I'm aware of, I'll wash my hands before doing the tank, but always dry them off.


Does anyone paint, smoke or use any perfume, deodorant, etc, in the room with the fish tank?
- no to all


Have you got buckets and hoses specifically for the fish tank?
- yea, I have dedicated equipment for only fish use.

 

[jordzcov]

Hi,
I add a pinch of tropical fish flakes that the fish store recommended, and is what I've always used, so there's no change there.


Nothing specific has changed. The only thing that comes to mind is that my cycle had crashed a while back, and then once I got the cycle back on track, algae and this oily surface began to appear. Other than that there's been no changes to the tank

 

[Colin_T]

It's probably the algae. We used to get an oily slick on the surface of some tanks when they had a lot of algae growing on the glass near the surface. When we wiped the glass down and removed the algae, the oily slick disappeared over a couple of days.

It's not poisonous because the fish look healthy and you haven't mentioned any dying. So increase aeration, wipe the glass down, especially near the surface of the water, and see how it goes.

 

[jordzcov]

It's probably the algae. We used to get an oily slick on the surface of some tanks when they had a lot of algae growing on the glass near the surface. When we wiped the glass down and removed the algae, the oily slick disappeared over a couple of days.

It's not poisonous because the fish look healthy and you haven't mentioned any dying. So increase aeration, wipe the glass down, especially near the surface of the water, and see how it goes.

That would make sense, as both seem to have appeared at similar times. Im doign what i can to remove algage, but that i dont seem to be winning the battle. Ive posted here (which ive seen youve commented on so thanks again) but hopefully defeatign the algae will remove this oly problem.


In terms of airation, i have 2 pumps/filters. One at the surface pointing upwards to help with oxygen and disturbing the surface. The other is then at the base pointing along the gravel. This one also has a phosphate remover as the fish store told me my phosphate levels were abit high when i went to them about the algae issue

 

[Colin_T]

Can you post a picture of the algae?

If it's blue green algae (Cyanobacter bacteria), it can be harder to deal with compared to true algae.

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Check your tap water for phosphates. If the tap water is free of phosphates, it is probably coming from the fish food and you might want to try a few different brands of food to see if that helps reduce the phosphates.

If the tap water is free of phosphates, do big water changes to dilute it in the tank.

 

[jordzcov]

Heres the thread

https://www.aquariumadvice.com/foru...and-destroying-plants-381028.html#post3583821


Yes it looks like blue green algae.

Can you post a picture of the algae?

If it's blue green algae (Cyanobacter bacteria), it can be harder to deal with compared to true algae.

-------------------

Check your tap water for phosphates. If the tap water is free of phosphates, it is probably coming from the fish food and you might want to try a few different brands of food to see if that helps reduce the phosphates.

If the tap water is free of phosphates, do big water changes to dilute it in the tank.

 

[Colin_T]

Yep the oily film is from the blue green algae. Get rid of that and the oily film will go.

 

[Andy Sager]

Hi,
I add a pinch of tropical fish flakes that the fish store recommended, and is what I've always used, so there's no change there.


Nothing specific has changed. The only thing that comes to mind is that my cycle had crashed a while back, and then once I got the cycle back on track, algae and this oily surface began to appear. Other than that there's been no changes to the tank

Reading through the answers, I believe Colin nailed it. I also don't see a lot of surface breakage. There's a good amount of rippling but not breakage that a bursting bubble would make. If you increase this, it can help keeping the algae from forming mats and the slick from holding together. I don't know what type of filtering you are doing but if there is a surface skimmer as part of it, that should also help keep the film from staying complete. If you do have a surface skimmer, lower the water level just a bit so the water has to rise enough to go through it and that will break the film and any algae mat up.