Smurf Account

So I have my main account on my phone and I started it ages ago. Like most new players I didn't really know what I was doing and spent a lot of time farming up useless heroes and then I stopped for a while. As a result I fell way behind with the arena and other things. Im just wondering if I could make a smurf account on my iPad starting new now I know what im doing, and not spend so much time doing useless stuff while I can still keep my higher account level and work on that as well. Does anyone know if this is allowed or against the terms and conditions and all that stuff or if you are limited to just 1 account per person? thought I would ask here before I went ahead and just made one and then ended up losing my main account!

Thanks in advance!