I have a 600 watt mh/hps with a dimmable ballast.. My question is with a 2x4x5 foot high grow tent can I start my seeds using the mh dimmed to 250 watts and then veg under the 400 mh and switch to 400 hps for flower.. Or is it more efficient to start with mh 250 use same for veg then switch to 250 hps for flower? basically just wondering what the best settings would be to best utilize this set up I have great ventalation running a 440cfm in line with 6 inch ducting and carbon filter although both fan and filter are outside the tent for room reasons. I am planning on 3 plants max in this set up. Thanks for any input.
Higher wattage = higher lumen output = more growth a 250w mh is still really good for veg and flower, but obviously 600w is better. As long as you can control the heat, go full 100%. My 600w on 100% only costs me like maybe $30 extra a month, but for seedlings you can cut it down if you're trying to save $
I have a 400 watt MH/HPS which is also dimmable and I start mine out at 50% actually. Then I move it to max by the 3rd week of vegging. You don't need that much light when these things are really tiny. After a couple of weeks when your plants get bigger, then you can start increasing your light output. This would also be as the plants require more space. I try to stick around 10,000 lumens per square foot or more since that is what the sun puts out. When the ballast is only run at 50%, you could probably have it a bit closer to the plants vs say 100%. Then when you crank it, lift the light up a bit to cover a larger area since it also has more light output at max. I think you will probably want to increase to 75% by your 2nd week of vegging, then increase to max a week later. I would probably start the flowering cycle at either 75% or 100% also.