Woah, I haven't seen one of those controllers for like 10 years!
FYI the Helios are fine, but you'll only get a fraction of the output compared to a proper reflector. Its probably about 25% of the output of an ATI fixture given 3/4 of the output is scattered not directed.
Full disclosure, I am affiliated with ATI. I have been selling T5s to reefers since 2005.