My Black Mollys are Acting Really Odd

[BlackMollyJenny]

I started my fishtank cycle about two weeks ago. I started with a brand new new all glass freshwater 20 gallon tank, a new Aqueon filter, a new all glass water heater set at 78 degrees, chlorine free "hard" water. I started with two mollys and a loach. I did a water change last week and one of the mollys died. My other Molly started turning white. I thought that maybe she was lonely so I got a new one and four guppies. Today the new one got a bunch of white scales. Their tails also started drooping and they don't get moved much unless I feed them. I'm really worried about them, what should I do? Please help!

 

[BlackMollyJenny]

Ok this is BlackMollyJenny again, one of my guppies died, should I be worried about my other fish?

 

[Fishlover3578]

Check your water levels make sure nothing is above what it should be

 

[Fishlover3578]

Do you have any pictures