Hi all, Im new to oscars and i have a 3ft tank. Will my oscars start to grow in there while i set up a new tank? And will it stunt there growth?

welcome to the site!
i will give my inputs based on your question:
yes, it will grow provided you keep the water in good condition and with proper feedings.
if your tank is 36 x 18 x 18, it is approximately 50 gal capacity, a little bit short but good enough for your oscar to grow normal with proper water maintenance and feedings.
hope this will help you.

fistly welcome to the site.

now your question is not as straight forward as you may think. there are many variable to consider before answering. first off when you say temporary just how temporary is it? also how big is the oscar your keeping? what kind of filtration are you using on the 3 foot tank? and how big is the tank(3x?x?)? are there any tankmates in there withthe oscar?

if you can answer these questions we can better understand your situation and offer better advice to your original question.

The guys r right we need a little more info to tell u what. U need to know I myself have a55gal(us) tank with 1 oscar and a pelco both r consider messy fish I have a biowheel 350 at the moment a I chagne the water every week so I can get a way with wut I got for now but I do want a bigger tank soon 120 or bigger but no more then 200 anyway u can pull it off for a while u just need to stay on top of matince if u can't u should get a bigger tank fast or give up ur o to a good home until u get a bigger tank remember oscars r a big commitment by well worth it hope this helps some good fishkeeping
Niterider