Need advice for blonde to red

Personally I never had any good experiences with permanent red. It faded after 2-3 washes and turned brown. I did my hair red with a semi for years witouth bleaching it. It didn't turn out as vibrant as when you bleach, but still a great red. I used SPX Blood red and SPX Cherry bomb. My virgin hair is a dark blonde/light brown.

Yeah, none of us here would recommend a permanent red, they fade very quickly to dull brown colour and are less long lasting than semi reds. They also require you to process the whole of your hair with bleach products every time you do your hair as you need to go over the faded lengths. Bleaching/bleach bathing just your roots and dying with a semi will give better effects and will be less damaging.

Basically what's been said.  Permanent reds have larger colour molecules, so they don't sit very well under the cuticle and wash/fade out quickly.  Semi reds have smaller colour molecules and actually stay in the hair for much longer.

Additionally, deep conditioning usually coats the hair with silicones and gives a false impression of healthy hair.  In order to truly assess the state of your hair, you need to clarify your hair, don't condition it and let it air dry.  You can then see if it's stretchy/gummy when wet or brittle when dry.