Well it looks like the two new additions came with a case of fin rot. Going to treat them tomorrow when i have chance to get out and get some meds.
I'll post some pictures of before and after so you can see the damage.
Rory and the fish with no name (Dennis) have had a case of fin rot, so the tank has been medicated, only problem with having devided tank if one gets ill there's a change the rest will, luckly, Blue isn't showing and hasn't shown an signs of fin rot. Which is good, because it's taken long enought to get his tail like that and it's still growing!