i was doing a water change before and so i cleaned the inside algea off the tank walls (it wasnt bad, just made the glass a liitllle foggy) with a mag-float cleaner, then i vacuumed the gravel, but now it was the filter..
i turned the filter off and once i picked it out of the tank to place in the old tank water bucket to clean, but as i lifted out of the tank, this black water came out which of course, completely went in the tank... :angry: it completely dirtied the water and made it look as if i put a little food coloring in it, it wasnt horrible but it was definitely not fine...

i thought it came out of the carbon filter or maybe it was sediment from the black gravel i have that was sucked into the sponge and came out with the water that emptied from the filter or just the black dye from the gravel (i cleaned it well but u cant get it all)...

so of course i immediately cleaned the filter as fast i could and put it back in to try to suck it back up, then put some water that i had left sitting for the re-fill in to try dilute it, and i can tell the oscar was not happy :angry:

the water is still foggy a little but a lot of it has settled... im not sure what to do to try to remove the filter without it ruining the water again next time...

so pretty much, the questions are:
has this hapened to you?
what the hell is the black liquid?
and how do i prevent it from coming out when i clean the filter???

It sounds to me like you have an internal filter, the black stuff is probably gunk that has been captured/grown in the filter. I have external filters and they get gunked up by cleaning time

Internal filters are usually not big enough to filter a tank with oscars in, if i were you i would invest in an external cannister filter. Get one that is rated for a tank twice as big as your tank. If you have a 55g get a filter rated for 110g

the coffee like dirt is actually all the accumulated dirt in the filter.
It's kept in there by the continuous flow of the filter.
Take a small bucket or can, that will fit around the bottompart of your filter.
Put the bucket into the tank and over the bottom of the filter.
While switching of the filter (or letting someone else pull the plug/flip the switch), you lift the bucket with the filter out of the tank.
This way the bucket or can will catch the waist, when the flowpressure of the filter stops upon switching off.
Works for me, for i made the same mess.
Allthough the ammount of mess in your story may suggest rincing a bit more frequent!

thanks guys, ohh and my oscar didnt even sulk... i guess he thinks hes a tuff guy now

anyways.. i havent logged on this in a while until now... so yea i might be on a lot today

Always go external filters for Oscars.
Internals are good for circulation only really ...and if its circulation you want then get a powerhead.