Good idea with the zip ties.... but
You don't need a water pump and sprayers. Use air pumps instead.
http://generalhydroponics.com/site/index.php/parts/air_water_pumps/dual_diaphragm/
Google: Bubbleponics
^^ Yup! This guy. Wish you'd throw up a journal at some point..
Edge you need to think about converting to dwc, that water pump is going to give temp problems. For shit's and gig's I threw in the one I have into my 6.5 gallons once and it didn't take 20 minutes to take my temps well past comfortable. Listen to whoever that LED (elly) guy is. lol very consistent, sound advice.
I would go ahead and leave both switches on in veg, unless you are trying to control stretch (stunt w too much blue).
What is the led's of each channel/switch? Any white's for mixing?
Plants use all the nm's of light one way or another.... just some more than others and in respect to the rest of the wavelengths. Right? Having the light on "full spectrum" and letting the light mix on it's way down is going to be better than over saturating it with a margin of the wavelengths it needs for Photosynthesis. (that first part's from my brother Tags, credit is due)
I would start back at 24-32" on full spectrum if it is a ~250w draw panel, if not 34-36" personally.
Then creep down like 2" a day, settling at 18" once shes established. Good luck grower