Knowing that there may be losses, rather than add the adults as I was planning I popped 5 juvenile (10mm ish) cherries in there last night. Had 2 losses and one isn't looking his best, so did a 50% water change this morning, will do another tonight and reassess it tomorrow.
The plants after doing well for the past couple of weeks have taken a slight turn. The star grass is browning a little, and the pearl weed has decided that staying planted is not for them. Moss is doing well though, as is the dwarf sag and the one that looks like a pea plant (can't remember what it is)