Water Problems

[iBetta]

So, I have been having some problems with the water in my Bettas tank.
It is very cloudy and have tried many things to help clear it up.
I read on another website yesterday that if you add some water in there from another, well established tank, it will help with bacteria, ammonia, nitrite/nitrate problems. Would this help? If so, how often should this be done? How much water should be added?

(16L tank, filter and heater(26*C))

 

[QuantumOptician]

Did you cycle your tank before placing the betta in?
The rest of my comments below are going to be under the assumption that the answer to this question is no.
The water carries little (~1%) of the beneficial bacteria, however it would help to get some filter media (as it contains most of the beneficial bacteria) from a friend's established tank. Also, check out this link to learn about fish-in cycling. And of course ask questions when you have them, there are very knowledgeable people here that are eager to assist you!

Edit: Forgot to add about the "cloudiness". I believe this a bacteria bloom, from my understanding this is the rapid proliferation of the "wrong" type of bacteria for a fish tank. I am not sure how to "fix" this, but if you wait for others they will have a better idea. Also, to help them out post your water conditions. Good luck!