which first plants or fish

So i finally kicked the wife out of the old green house. after cleaning out all the junk and treating it to new panels im going to build a fish pond.
The size will be 16ft x 4ft and 3ft deep.  

So......once it's installed and filled with water.. what should i do next. put in the fish or put in the plants...

i still have a lot of research to do.  

thanks, Regards Phil

I have a friend that designs aquaponic systems, he says you want to start with plants because they're more resilient and will prepare.the water for the fish to thrive

Thank you S.Lowe, would you ask your friend for me which plants he would recommend please.

I plan to stock the pond with Tilapias and possibly a few trout.

Regards Phil