How do I dim a DX 18 hybrid?

[Science/G]

I am adding a DX18 hybrid T5 with only 2 bulbs, ATI true actinics, for fill and to hit that 420 nm spectrum on my 30 gallon mixed reef. I don't want to burn out my AI prime UV and violets LEDs. Dave at Aquaticlife recommended a dimmer controller, but I would rather not drop another $200. The hep ballasts are dimmable. I tried a hack, but it didn't work. My knowledge here is limited. It's not a lot of light added,
2X24 watt bulbs. I am concerned however with the UV burning up my reef without an acclimation period. Is there a cheap solution or should I not worry about the intensity and just manage the lights by photoperiod? Any help would be greatly appreciated.

My Hack

 

[eliaslikesfish]

bump!

 

[Science/G]

Ok so I ate the $200+ and bought the controller Dave with Aquaticlife recommended....I am not taking a chance with my reef. Feel free to now comment about how I could have accomplished my goal for $30. Lol