Can a MH ballast, in particular Icecap, rated for a 250watt bulb run a 175 watt bulb just as effectivly? Or would there be any side effects? (i.e. rapid aging of the bulb, flickering etc..)
Will it light the bulb? Yes.
Will it burn it out prematurely ? Yes.
Will it flicker ? Probably not.
Will it have the same color that it is supposed to ? Nope.
Will it cause heat issues ? Yes.
Will it break the bulb? Probably not.
With some bulbs it might not even light it because they are designed to run at certain frequencies which might cause flickering (Icecap Ballasts will light any bulb because of its design). The bulb will not last more than 4 months tops and the color will shift faster if not immediatly.