You're asking a lot of questions tonight
Good for you though...its best to ask when you don't know. I suggest you make one post where you describe your tank, your experience level and your water parameters...then ask several questions under one post. It will help members here give you good advice.
Do you have drift wood in your tank? When you do a "cleaning", are you doing an actual water change? If so, what percentage? Do you use any chemicals? How many fish do you have in what size tank? What type of fish?
Your answers to any one of the questions might give someone a hint as to what is going on with your water.
Take care...