Corals get what they need from PAR and PUR. You can't really measure how useful a light is going to be from BTU.
It gets tricky depending on what kinds of corals you want to keep as some have higher intensity lighting needs that others.
When it comes to keeping corals, your options are T5HO, MH
, or LED
. Not all LEDs are created equal, as the one you are looking at would only light up your tank and not meet a coral's photosynthetic needs.
Here are some examples of what will work LED