Is the use of the capacitor optional? Can I use a 400w HPS or MH bulb with a ballast and an ignitioner but without the capacitor? What would be the difference?
I have no idea what this dude just said lol but to answer your question you need a capacitor. I had 2 refurbished 400 watt lamps with the balasts shipped to me and one had a bad capacitor. The bulb lit up but only had about 25-30% ( guestimate ?!?! ( i know i hate the word to but thats what this is ) ) of the output of the other lamp. So yes you definitly need a capacitor. The guy who refurbishes them just sent me a new capacitor and i wired it up my self you shouldn't have any problems doing it as well