Just the hair algae
. I didn't notice any growth in the chaeto. In fact it was getting losing its colour. I'm not sure if it was because the lights were too bright or if I didn't have enough flow through the reactor. I think it may have been the latter.
I may try this again a bit later on a separate frag tank I am planning on setting up. I didn't want to mess too much with the display tank. I didn't want to tinker with it so I switched over to BPs that I had used with success before.
I am sure this approach could work if done correctly though. Others have had success using the non-pac bellum reactors on other forums that I have read. Heck people have had success growing chaeto in their aquaclear filter (which is why I think it may have been flow).