betta fish water continues to cloud

Question
Hello. I've had my first male betta fish for a couple of months now. He's in a 2+ gallon glass jar, aquarium stones&rocks on bottom, a couple of sword plants, small hydro sponge filter with air pump turned down so water relatively calm. Always treat water before changing it, and let it sit out.  Was doing partial water changes 3x a week, but water still got cloudy. I tried Algone, but that made it worse. I put betta in another jar, scrubbed out his main glass jar, rinsed very well. SInce I have to be away sometimes for several days, wanted a situation where water ok for longer. Tried Fritz, and then Stability to add nitrifying bacteria. (Tried in sequence - not at same time).  Both say tank will "cycle" quickly and safely -- but the nitrite levels go up too high within a day. Fresh water changes, even up to 50-70% don't bring them down enough, so last couple of times I did complete water changes. Even without adding bacteria (maybe from rocks and filter), nitrite goes up to what looks like .50ppm in a couple of days.
 Also, now third day after total water change (about 1/4 new water on second day), and water is suddenly cloudy again!  Shall I take rocks and plants out? Do I have to do a total 4-6 week "cycle" in another jar and put him in that?  Betta doesn't show signs of illness in terms of anything on outside but he's clearly listless and hangs out on the bottom or just hangs in tank now, when he used to swim actively.
I've been feeding him, alternately, pellets, freeze dried brine shrimp, freeze dried bloodworms in small amounts recommended. Skip a day every week. Tiny piece of cooked pea every other week on day I don't feed him anything else.
  Using API test kit for nitrite and nitrate (nitrate seemed about 10ppm last night), and both Seachem test kit and alert in the jar to check ammonia. Have an in-jar thermometer and temp between 78-82 so far.
  Have read all kinds of things on the 'Net and gotten various advice from local stores -- but either I'm doing something wrong, or claims for Stability bacteria or Fritz not spiking nitrite are wrong. (I used them in sequence, not at same time).
  Please help me help the little betta. Very much appreciate any suggestions. Thank you.

Answer
Sara,

 Did you cycle the tank for 2 to 3 weeks before adding your Betta? The problem is, you are over cleaning your tank. The filter needs bacteria and when you scrub the tank, you remove it. So every time you do that, you reset the filter and starts to cycle all over again. Also, with the size of your tank, and the amount of water changes you do, the filter is unnecessary. All of my 11 adults Betta's are in 2 gallon tanks with no filters. What I would do is, do a complete water change, and remove the filter. Make sure you condition the water before adding your Betta, and make sure the water temp is the same temp as the tank. I would also keep the heater at 82 degrees. The fluctuation in temperature could be a contributing to the  listlessness of your Betta. As far as the water conditioner I use Aqueon Betta Water Renewal and it works great.

If after you remove the filter and get him in the new water, and things don't change, let me know and I will help you find the problem.