Lets talk UV:

I use the Migro UVB fluorescent tube 75% uvb 25% uva (€95).

20w and the tube is replaceable (€35)

Height 50cm from canopy.

Duration 2hrs mid light cycle (hours 8-10 of 12) the final 3 weeks of flower.

Observation over 6 harvest is that there is a noticeable difference in trichome production and structure (larger thicker heads). I also noticed a quicker finish by 3-5 days. I would definitely recommend.

Bonus Shane from migro answers the phone when you the shop. Fantastic customer service!