How to cure bv? Does BV use semen for food? If so, would using condoms cure bv?

Antibiotics. Bacterial vaginosis is treated with antibiotics such as metronanidazole. Semen do not provide food for these bugs and condoms do not "cure" it, although they are always recommended unless you are in a long-term, completely monogamous relationship.
Decrease acidity. Semen is loaded with carbs, and the common BV bugs may consume it but lets go for a cure.Decrease the ph in your vagina by using a very dilute vaginal wash of 1 tablespoon of clear vinegar in a quart of water.I do recommend condom use to prevent disease and pregnancy.