The other day i got a complete 10 gallon tank from a friend. i washed the gravel before setting it up, washed the tank and the decorations (silk plants, rocks) inside it. The tank was set up for a whole day before I took my new betta home. However, the water is still slightly hazy, and I thought it was just because I had moved things around inside it. I assumed it would have settled and cleared by now but the tank has been up for over a day. I'm not sure what the cause is/is it dangerous to the fish/how to clear it up?