If you look into PAR alone to decide your best fixture, you are going to make a big mistake.
Change the bulbs and you will change PAR as well! Big time.
PAR is only part of the equation.
What your PAR meter shows isn't necessarily the best for your corals!
PAR is also a great way to make videos and SELL fixtures!
Grandis.
In this case however, the ATI costs only a fraction of the Spectra so not sure BRS is really gaining much by showing that the lowest cost option actually has a lot more PAR...
At the end of the day it's results that count and again here both T5s and MH have an enviable track record of awesome reefs so I guess T5s are the cost effective way for coral health [emoji4].