Hello, I'm new to this forum. So I bought another tank for my betta about a few weeks ago. It's a Topfin 3.5 gallon with led lights and a filter . Before, he stayed in 1/2 gallon without a filter, and did pretty well. I used deer Park spring water and rinsed put his tank every 2 weeks. So how does using a filter work? His water appeared to be a bit cloudy when I turn off the LED light and I'm not quite sure what to do.