CRA carries Reed Mariculture's stuff including a bottle of Tigger pods, although copepods including Tigger pods are benthic and don't seem to live on algae. I see a lot of amphipods living on my macroalgae. You may already have some pods living on your macroalgae since they often hitchhike on live rocks. If you shine some light on the substrate and rocks at night, you might see them moving around.
Tomoko