wrong spectrum for flowering

If I used wrong spectrum for flowering would it effect my yield a lot?

yes....what did you/are you using?

I'm still vegging with a t5 4 24inch 24 watt tubes 6500k nd the hydro store doesn't have 3000k nd I need to flower already or the kryptonites gonna get to big

I use the same spectrum for veg and flowering. It´s called the sun.

You'll be fine. Sure, its not ideal, but you'll be fine. Think of it as the difference between low-grade and high-grade gas in your car.