You don't need a reflector for VHOs, just buy UV/URI brand bulbs next time, as they've got built in reflectors.
You should really just use the VHOs for coloring the tank (use SuperActinic bulbs for each VHO, buy them at CoralReefFarm, good prices

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Use the halides for the lighting support. The only issue though is how deep is the 150? If I remember correctly, the 150 is like 29" deep (kind of a weird almost custom dimension) but if that is the case, with 175w bulbs, you'll only be able to keep SPS and most clams in the top 1/2 of the tank, with the lower 1/2 reserved for softies, zooanthids, most LPS, etc. For a tank of deeper than 18", you usually want to go with 250w halides, until you go more than 24", then you want to get 400w halides GENERALLY speaking of course.... I'm sure anything can be done with any combination of lighting.
My suggestion would to be use high output bulbs for your halides (10k XM or something to that effect) and use the VHO for actinic supplementation (adding the blue color to the white of the 10k), that way you get more light deeper in the tank.
Anyway, hope that helps
