Freshwater, my tank is very cloudy an ive tried something, not much luck..
Has the tank been set up recently if it has its probably an algae bloom. It's a normal occurrence with new setups and will go away in a few days by itself or you can get some already established filter media and stick it in the filter to "seed" your new filter and that will cycle your filter and make it go away faster. This is all assuming your tank has been set up recently.
You should monitor your ammonia nitrite and nitrate levels with liquid tests if your tank isn't established yet there won't be any beneficial bacteria in your filter media and when the fish produce waste the ammonia won't be processed to nitrites and the fish will get stressed out. Let me know if u have any questions about it. Good luck