I recently got a female Betta and had her in my heated fancy goldfish tank. They were good together(after the Betta got used to being there) but feeding time was bad. I had to separate the Betta behind the filter(she stayed there a lot) and feed her because the goldfish ran her off and ate her food. I decided to take a chance and put her in with the guppies and mollies(two male guppies and two red tailed mollies). I rearranged then decoration/hiding spots and put her in. They immediately started chasing and biting her. After a minute and it didn't stop I took them out and put them in with goldfish until I can get new tank. One of the guppies started attacking the telescope's eyes and I put him(the guppy) in the quarantine tank The goldfish is fine but stressed. My question is, will the mollies be aggressive to the goldfish? They were very aggressive toward the Betta. I read they can be. The one guppy in there isn't really bothering anyone and the mollies don't appear to be but I'm afraid to leave them alone. I don't want to go to bed tonight and wake up with injured or dead goldfish. What should I do? I didn't know the mollies were aggressive but they and the guppies chase and bite each other constantly. I tried to make the Betta's life better and now everyone's unhappy. Should I put them all back to the way they were?