yellowish, cloudy betta water

Question
It is a small tank, maybe half a gallon. no filter. water is room temp.  clean it once every week or week and a half. feed twice a day 3 pellets at a time.  The appetite is fine seems like a happy and healthy fish.  very active and makes nest.  But after a few days the water gets disgusting with this white cloudy stuff.  Then the water turns yellow after a while, and the water in the tank slowly goes down.  Probably becasue there is no cover on it.
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Followup To
Question -
My betta, jessico, has yellowish, cloudy water.  There is white or yellow cottony floating fungus looking thing.  I have changed the water a few times and cleaned all the rocks, a few times.  It just returns.  I am using declorinator in the water.  If you have any suggestions or information, it would be much appreciated.

         Thnaks,
         Steve
Answer -
Hi Steve;

What size tank does your betta have?
Is there a filter in it?
What is the water temperature?
How often do you clean it?
What kind of food do you feed, how much, and how often?
Does the fish have a good appetite?

Let me know as soon as you can........

Chris Robbins

Answer
Hi Steve;

You may be overfeeding. Bettas only need a total of 2 to 4 pellets in one day. Even if he eats all of them you have been feeding, a lot of it will go out as waste because it isn't digested completely. It then becomes infected with bacteria and/or fungus and fouls the water. So, cut back on the amount of food and see how it goes.

Followups Welcome

At Your Service;
Chris Robbins

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