Had to look up that bulb. Nice!Alternatively - Yes, it would take about 5 years using the most expensive bulbs to equal prices. Will that LED fixture need to be replaced in 5 years? They lose par over time. MH will just be replacing the bulb still. Also, I used to use the plusrite 400w 20k bulbs and they were beautiful. $10 each. They dont make them anymore. I am trying the catalina 400w 20k right now. $30 each. I fired them and they look really nice so far but dont have the tank yet. Reefbrites are around $80. Also, I used to replace bulbs about every 18 mos, not once a year. Plus, for a lot of people, it's not easy to drop $400+ for a single fixture. Especially if you need multiples.
My xr15 gen 5' are 4 years old and I bought all 6 used. They are still running and par has not changed at all so yea I don't know how long they last.
I run RB photons on my ext 170.
I went with them after researching them and I followed Therman's threads. He has had the running for 10years, so again unknown life span.
My old 120 on Halides and the 18" nano cube on 16hd's, the leds that convinced me leds work quite well.
Both tanks were running at the same time.

