Oily Scum On Water Surface

[blueally]

Hi all, please excuse me if this question has been answered before but i'm a newbie on site. I have a 4ft community tank, mostly guppies, recently i bought 4 new guppies from a local shop. 1 died on the way home and the others died the next day, now all my guppies are starting to die ( I have lost 12 so far), the water in my tank has been checked and is ok so using your site I have diagnosed what appears to be a fungal disease, but nowhere has it been mentioned about the water having an oily scum on the surface, have I mis-diagnosed?

 

[WILDER]

Do you feed frozen foods to the fish, also how big is the tank, what fish and how long has it been set up.also were there any signs of illness on the fish like fungus, spots flicking and rubbing against objects, tummy bloated and could they maintain there balance in the water.

 

[blueally]

The tank has been set up for over a year now, it is 4ft long x 18inches height x 1ft depth. About 30 guppies, 2 glowlight tetras and a loach which are fed exclusively on flaked food. All the fish have been healthy and the guppies have bred many times in the tank, there were no signs of disease until I brought in these new guppies.

 

[WILDER]

To remove the oil from the top of the tank float a peice of kitchen paper on top of the tank water, that should remove it, some foods cause an oily water surface, what shape were the guppys in when you bought them, in could be a bacteria infection, have the guppys that are left darkened in colour.

 

[blueally]

1 guppy died on the way home and the others died the next day!! Obviously something wrong with them although it wasn't apparent at the time, they must have introduced the disease into my tank

 

[blueally]

The guppies that are left have not darkened in appearance.

 

[Tolak]

Usually that oily film is a sign of not enough surface movement. Either add an airstone, or drop the surface level if you have a hob filter.

It's a really good idea to quarintine any new fish you get in. This prevents any spread of disease that the new fish may have.

Tolak

 

[blueally]

Thanks for your help guys

 

[WILDER]

If they have darkened in colour you need to treat with anti internal bacteria med, good luck.

 

[rdd1952]

I have the same oily film on my tanks. If I leave teh surface completely without movement, it gets very think. I have added airstones to the betta tanks since I definitely don't want their surface to be covered. I don't have a clue what causes it. I took one of my 2.5 gallons down, scrubbed it with a bleach and water solution and then set it back up and the film was back in about a week. I guess it is something in the city water supply. As for removing it, I have found the best way to be taking a plastic drinking cup and just barely submerge it so it kind of skims the top off. I do this at every water change. It takes a little time but will remove most of it. This film is the main reason I went with Fluval cannister filters with surface skimmers for my 75 gallon. Hopefully the surface skimmers will keep it pulled off. I haven't seen any on it yet and it has been cycling for 2 weeks now.

 

[black angel]

I notice in your sig of the betta rdd1952 that there is scum on the surface of the water and your finger is in the water. A lot of the surface scum is from hands being put in the tank. The hand secretes oils all the time and that is what causes the oil slick as well as well as any soap that you use to wash your hands with.

 

[rdd1952]

I guess that is a possibility but I do wash my hands everytime I start to do something in the tanks. The reason I believe it is in the water supply is that the 2.5 gallon that I cleaned and started over has never had a hand in it as I ran the water straight from the tap into the tank along with the dechlorinator. I have on a couple occasions run a bucket of water and just let it sit. After about 48 hours I can see a very light film forming. All parameters check fine (everything is 0 with pH about 6.8 to 7.0) on our tap water so I don't know what causes.