It depends on your seriousness. as much serious are you can switch to real account so rapidly. here serious means not only practice on demo account but also learning about forex trading, technical analysis, making your strategy and applying it on your demo account and evaluate. when you satisfy switch to real account. it may take 3-6 month or more in some cases. but don't wast time after demo account too much because you cannot learn one very important thing in demo account that is controlling emotion as real money is not concerned here.