My oscars are growing differently in size. Is it normal???
One of the oscars is getting longer, the other one is gaining vertical height.

The are around 4 months old and both of them ar around 4-5 inches long

Same goes with mine.. (2 lutinos). Based on my observation, they have stages of growth.. Like for example, the first month I got them, they grew longer. The next month, they grew vertically. 3rd month, smaller one continued getting longer and the other one vertically. It's like every month they change their way of growth. That's just based on my experience with mine though..
Now, the bigger one's around 7' and the smaller one's 6'.

Yes all sounds normal to me. i had 2 before, a pair from the same parents. I knew one was female the other I never knew. I got them both the same size about 2". one grow at a very fast rate until it reached 6"(also got fat) the others growth was slower but faster once past 6". both ended up the same size length wise but the slower growing fish had more height,

just a few posts down is the same question ))) just shows how common it is. ))))but still a worry if you are not sure.
www.oscarfishlover.com/oscar-fish-advice...g-at-different-rates