need help asap please

hi as you all know I have a 30 gallon tank and wanted to know how a filter system will work for the tank I have a lil filter that does not seem to be doing good so i want to buy a new one?? what kind should I get and I dont know how to instale it , does it clean the water?
I have a baby black moor in the tank and i want to change the filter and i dont know how to do so.

 

What kind of filter do you have right now? What makes you say that it is not working? Do you perform water changes and is the black moor your only fish? Filters really do not clean the water all by themselves. They keep the water parameters in check until you perform a gravel siphon and partial water change.
Let us know!
Give us your readings too... ammonia and nitrate, at very least.

 

the guy at petco said that i didn't need an amonia checker or so on...I have one baby black moor in the tank , I was wondering how to go about setting it up to be a comfortable place for him.

 

The guy at petco lied (or didn't know what the heck he was talking about). You need tests for ammonia, nitrIte, and nitrAte. Those 3 things are present in uncycled tank (like yours) and can very easily kill fish. They are colorless & odorless so unless you have the tests, you have no way of telling if they are present and your fish is in danger or not.

And like Hooben said, we need to know what kind of filter you already have, why you don't think it's good enough, what those test results are, and how often you are doing water changes. Without knowing those things, we really can't even begin to help you.

-Chelle