More on the lines of taking some of your livestock out. AKA fish. Having too many fish in that small of a tank could be producing too much of a bioload. In other words they poop too much and the waste doesn't have enough time to break down. This will result in your levels being elevated and would result in sickly fish. Please go to your LFS and have them test your water and pick up a test kit while you are there. As long as you can't provide us test results, you will just keep getting hounded by people here for them.