Another question for you lot,
iv had my fish for about just over a month and they have tripled in size.
How long does it take them to get to 10" and over.Does their growth slow down as they get to around 6 or 7 months?

about a year, maybe a little longer, and yea, they slow down considerably after about he first 9 months i would say, but you can still expect them to grow pretty quick.

mines maybe a year and a half at most and is 11"

Will probably take approximately one year for an Oscar to reach 10 inches. Once they get to around 10 or 11 months, the growth rate does slow down quite a lot. Many fish are different, they don't all grow at the same rates, & and do not end up the same size. Aquarium size, water quality , many factors determine how you Oscar grows.