it looks like i have an oil slick on top of the water in my fish tank. i have changed the filter (rinsed it b4

Question

i put it back in) i changed a 1/4 of the water (put chemicals in the water in seperate pitcher b4 i put back in) ph meter reads ok, temp is between 72-78 degrees. And 2 of my bala sharks died a minute ago. wtf? anyone have any answers? please tell me bc my girlfriend is FREAKING!!!!

Answer 1

That is just a protein layer that comes off your fish food. It's not harmful to the fish generally but it can be an eye sore :)

There is two ways of getting rid of it, you either skim it off by removing it while doing a partial water change or you can split a two ply tissue paper or kitchen roll paper into one ply and drop it flatly on the whole water surface. When you see that the whole tissue/paper is soak ( in a second or two) lift up the tissue paper and the layer will stick to the tissue and be removed with the tissue.

If you need a long term solution, you will need something called a protein skimmer. :)

As for your bala sharks dying, it probably due to Ammonia poisoning (please do a test), I gather that because you said you change the filter ( or rinsing it too clean, especially under chlorinated tap water), I suspect you might have no or very little bacteria and you are facing an Ammonia spike. You might have to do a mini-cycle if you over rinse your filter or a complete cycle if your filter or filter media is new.

Hopes this helps.

.

Answer 2

The film on the surface can be from a few things - one of which is your water conditioner. You can test that easily enough by adding some conditioner to tap water in a separate container.

Another potential cause is the fish food you use. All foods need to contain some amount of oils/fats, and if yours has a high amount, well, oils/fats that soak out of the foods float on water. If the conditioner wasn't the problem, let a few pieces of food soak in the water and see if it gets the film.

A third possibility is that your tank is due for a cleaning. When food containing proteins is eaten or decomposes, the proteins may dissolve somewhat in the water. In saltwater tanks, protein skimmers are used to remove this, but they aren't terribly effective in the lower density of freshwater. Since the proteins give off ammonia, the bacteria are attracted to the molecules, and they're what gives the film something of a rainbow sheen. What is effective is skimming the film off the surface with one of these: http://www.thatpetplace.com/pet/prod/215642/product.web The flexible hose attaches to the intake of your power or canister filter. I had my doubts about them when they first came out, but bought one to try in a catfish tank (which had a nice oil slik of it's own), and it did work to remove it. About 3 companies make these, so see if you can find one at your local pet/fish store.

Answer 3

well no crap they died. You shocked the hell out of them by over cleaning the filter and doing a 25% water change! I get the coleration on the surface of the water too sometimes, it goes away if you move more water on the surface, it could just be debris settling from the air in your house, do you burn insense? smoke? Have an oil burner? just fire up the furnace for the first time? It can also be natural gas. A fish tank is a natural gas WICK. How do you feel? Look for the contamination source, also try different food, the food may be contaminated. But for god sakes! don't over react! Chems, Cleaning, Water change, too much at one time is bad.

Answer 4

take a glass or plastic cup (be sure it is very clean and no soap or oil on it) and stick it into the tank straight down. as the water get to the top of the empty glass slowly push it down just slightly farther and the water will fill the glass. you will be skimming the top of the water. this will remove the oil slick. do not over feed and keep water levels good. leave water sit in some thing for a day before you put it in the tank.