are warm white correct for budding??

Do as heavy fuel said and experiment , i would use 50/50 or go for more warm than cool.
I used an old sunbed with eight 6ft tubes total of 520watts , this give me 12 square feet of even light which i could get close to 20 plants under.
Keep em short and the lights close.
Disco.....

I've used a sunbed before but I had to chop it down to 4ft, can't get 6ft cool whites near here. I'm using sets of 5 at the mo, 3 cool 2 warm, but I'll swap to 3 warm on one set and see what happens, Tech. I like playing.