have a 120 gallon setup, undergravel filters, two powerheads on pipes, carbon filters on different pipes. washed gravel and 1 piece of washed and soaked bogwood. setup has been running for a week and everything was fine. put two oscars in and two plecos. throughout the evening things were fine, woke up thismorning and everything was cloudy and dirty. what happened when the lights went out? any help would be great. thanks in advance.
brian

welcome to Oscar fish lover

This is an easy question to answer, you're suffering from what is commonly called "new tank syndrome" Unfortunately you have made one of the most common mistakes people do when setting up a new fish tank. I don't think you have cycled your aquarium, and you have definitely put too many fish in there to begin with. Basically, there is not enough beneficial bacteria in your filtration system to deal with all the ammonia that the fish are producing. So what's happening is free swimming bacteria are building up in the tank water and that is why the water has gone cloudy.

Have you got any test kits? At the moment, you want to be testing for ammonia and nitrite. Like I've already said, and mania is what is produced from fish waste. Once you have a little bit of bacteria build an open your filtration system, they will consume the ammonia and converts it into nitrite. And that going to go into great detail because it might just confuse you. All the information about this is on the website, and helpful articles, I suggest you read it very carefully.

So, you need to test your water for ammonia. You have probably got in the water now so I would suggest doing a 25% more for change straightaway. Is it possible that you can lose the plecs for the time being. Although I don't really like them and wouldn't recommend people keeping them because of the size and reach, if you want them back, you can always get them back later. However, with all the fish you've got, they're going to produce lots of ammonia, even small Oscars will produce a lot of ammonia. Even though you need ammonia present so that the bacteria will start building up in the filtration, you don't want too much building up, if this does happen, it will kill your fish, or put them on the great stress and probably damage their health for life.

Okay, I'm not going to bombard you with any more information, try and take this information on board. Tell us if you have got some test kits

Admin, First off thanks for the rapid response. I do have test strips, reading as of thismorning is:
Nitrate = 20ppm
Nitrite = 0.5
Hardness = 120
Alkalinity = 180
PH = 6.8
I had aquaculture in school so i know all about the two bios nitrosomonos and nitrobacter, however I honestly felt that running the tank for a week would be long enough to establish some type of control in it. obviously not. new water is conditioned and bubbling will do a 25% w/c tomorrow morning sometime. Took the wood out and am soaking it some more just to make sure it isnt that. right now have some temp filter media in it running to tackle some of the free floating ammonia. Thanks again for all your help.
Brian

ok you will still need to test your ammonia, this is an important reading at the moment. the cycle could take as long as 6wks, 1 wk is no where near enough time. retest daily and water change if reading for ammonia or nitries are present. the info above is correct, with your current stock all could be lost. whats in your filter?? it should hold foam and a tube or block type media all the time.