One of my 75
FW tanks has nothing but livebearers. I have a lot of floating plants in the top and regularly catch the babies to feed to the other tanks. Other than that, I'm a little funny about feeding store-bought live foods to my stock. Depending on what you get, you can introduct a lot of problems into your system. Live brine actually has very little nutritional value, although the fish love it - like candy to a baby. Black worms can contain leeches that can get down in your system. Some live foods can carry diseases. If you use live, always make sure you rinse it first. Frozen will kill any of the bad stuff you can introduce with live. I feed a variety of frozen foods as well as Spectra foods. I've been keeping tanks for over 30 years and its always worked for me. I currently have 7 totalling 400 gallons. They include a salt water reef, salt water aggressive, two 75 gallon fw and several breeding tanks.