That is known as "New Tank Syndrome". Depending on many factors, mainly
filtration, aquarium size and number of fish, the cloudiness may appear on
the first day or wait for several weeks before occurring. This is a normal
adjustment the tank must go though to cycle. The cloud is mostly bacteria,
(not harmful to the fish) You may want to check your ammonia and nitrate
levels. Hope this helps.


"Adam Gottschalk" wrote in message
...

I have a tall 15g (15H) tank with an under-gravel filter. It's been
running a little more than a month. I put a couple of feeder goldfish in
it a couple of weeks ago. Things have been fine. I've done weekly
partial water changes and have scraped the glass a few times. The pH has
been steady about 7.4. I removed the comets and put a couple of mini
fancy goldfish in about 4 days ago (Siamese Dolls). The water still
tests fine, but it has gotten cloudy, like milky. When I do water
changes, I rake over the gravel/river-rock and vacuum it. Been feeding
once a day, pellets soaked in aquarium water. I haven't changed to
carbon cartridge yet. Any help appreciated.