Done cycling?

I would start slow, you do not need the entire CUC at this point. There is a good chance they will survive. If you want to increase additional flow in that tank replace the stock pump with a RIO 1100, it has made a huge difference for me. I highly recommend not using the biocube filtration unless you are very good at cleaning the bioballs (i.e. nitrate traps). Do you have the HQI version or the standard biocube?

 

the algea bloom is a really good sign that your cycle is ending! Every cycle I have gone through ended with a nice brown algea outbreak. Kill your light schedule for a bit. I dont see hwy you cant get a small CUC. Just make sure you dont add too many, and every week or so drop a piece of flake food or something for them to eat in case they dont have enough