There are people on this forum that think a reptisun 5.0 t8 is a great bulb.
There are people on this forum that think a arcadia 6% t5HO is a great bulb. Its about 10x more powerful than the above bulb.
There are people who dont really want to sell you an arcadia 12% T5HO without a meter or at least ALOT of experience. It is 2-3x more powerful than the 6% above.
The average Merc vapor is 4x more uv per meter squared at the same distance, compared to the 12% above.
Vets/zoos literally use the same 150watt merc bulbs, for 30-45min a day 2ft away, to help with bones of dilapidated large full sun lizards.
Now you do the math, how many orders of magnitude is the merc vapor over the "recomended" T8 5.0?