They have those hang on the back filters i use them for my betta tanks, they
work good and keep things clean, i think the ones i have are for ten gl, but
work good for it. Also, just a note, i have a big goldfish, which is how
most wind up as long as they live, mine was a feeder for a pacu, who got
saved, he started out about the size of a guppy and now he is very big, he
could not turn in a 2.5, i dont think he could live even in a 10 gl. he is
in a 29 gl being moved to a 55 gl in a week or so.
Nik
do some water changes like 10-20%,




"Ben Rum" wrote in message
news
I've recently purchansed a tinly little 11 litre (about 2.5 Gallon I
think) tank for 2 goldfish. It came with a little filter which obviously
isn't doing a great job as the water gets cloudy after about 3 days, after
a week it's quite murky - still see through, but not pleasant to look at!

I understand that 2 fish may be too much for 11 litres, so is there
anything I can do to keep their environment a bit cleaner?

I feed them 3 times a day, and generally not more than they would eat over
a 3 min period (as per several web searches have suggested)
I also refresh about 10-20 percent of the water in a week, however this
doesn't help enough.

Any suggestions would be appreciated, as I want to keep the two fellas
happy!