How many manifolds do I require for my StarFish system? One of the advantages of StarFish is that you can mix and match parts to build the system that suits your application. Manifolds are optional parts, but are generally included when using flasks in StarFish. If you would like to have water condensers in your StarFish system, you will need two water manifolds (one for water in, and one for water out). If you want to use vacuum or inert gas too, then you will also require a gas/vacuum manifold.