Discussion in 'Growing Marijuana Indoors' started by jay bone, Jan 1, 2013.

  1. Quick question probably a dumb one sorry....... I have a 400w mh ballast would it screw something up if I use a 400w hps instead? If I can't then my next question is will it hurt my seedlings in rockwool if I have to use 600w hps light instead of 400 mh as long as I keep the distance between hood and babies to be THANKS IN ADVANCE
  2. #2 Calismokerlives, Jan 1, 2013
    Last edited by a moderator: Jan 1, 2013
    Not a dumb question its kind of a debate and personal choice of fucking up your system/ballast but me personally. >>Unless the ballast is convertible DO NOT screw in a 400w HPS INTO A 400W MH ballast :). And no your seedlings will be fine aslong as you have proper vent/airflow/temp/distance or hieght etc... With the HPS in veg they tend to grow taller instead of bushy but nothing to worry about unless your buttplugged for height.

    Happy growing
  3. Thanks that's what I was kinda thinkin but this is my first and can't wait to master the art I'm sure people on here are tired of hearing my questions but I'm REALLY THANKFUL FOR THE HELP thanks...... hey where you from if I might ask?
  4. You are likely talking about magnetic ballasts. An MH magnetic ballast will not fire a HPS bulb because it lacks the starter that the HPS bulb needs. Some magnetic ballasts have a starter in the circuit that you can switch in and out so you can use either MH or HPS bulbs. Your ballast would have a switch on the case that would indicate this.

    Although an MH bulb gives a better spectrum for vegging you should be fine running that HPS bulb during veg.

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