OohFeeshy
It's only forever; not long at all...
If I am calculating right, the tank is about 25 ish gallons (going by the 120l Slyspy mentioned) It is too small even for the 3 orandas. Take them and the sharks back if you can. If your son really want a goldie, get a cheap 10 gallon tank and either have one common or fancy. I can't remember what else you've got, the mollies, neons and maybe the barbs (I know nil about them) should be OK, but you really bought far too many fish. Your tank is waaay overstocked, even though it doesn't look like it at the moment. You might be OK with the plec, I'm not sure of the dimensions of the tank and not knowing how big barbs grow, I can't really tell you about that.