Do i need nutrients?

Do I need to use nutrients in the growth cycle as i am using mg soil which has enough nutrients to last me till the flowering cycle ???

it sucks that you are using MG soil. since mos of it is time release. It usually takes 3-6 months of watering to flush that shit out. you should be fine, however you bud will taste worse if you dont get a chance to properly flush.

You'll be beter off without nutes. IMO
Just don't over water.

So if i use a normal potting soil and no nutrients untill flowering things should be ok i will be using fishtank water which contains nitrogen n shit ?

You said mg soil. You need to watch the plant if it need something it needs it.

yeah just keep an eye on your plants, they will let you know when they need something