I think one of my minnows is pregnant. I dont know if I should just leave her alone or if I should separate her from the other fish. Any help would be appreciated thanks.

They're egg layers and the male must be present to fertilize once she's spawned. The problem being that you don't know which male will fertilize them(if any). JMHO, but leave her in there and watch her to see if she drops her load and if other males will fertilize. Once done and the fish leave(some species are parental), you would need to section off that part of the tank where they spawned so no other fish are in there except the fry when they hatch. Been almost 35 years since I dealt with spawning fish and they were tropicals. I had to separate the fish from the eggs once done so they wouldn't eat them.

 

Anyone else more experienced with egg-layer spawning have better advice to offer?