So I'm curious I'm running a 400w MH right now. I also have a 1000w MH. Can and should I be vegging with that light set up instead. For some reason guy at store told me to go with the 400 when I went there for a 600 ballast bulb combo.
Hi all ... another Baystater checking in.
Just a couple of thoughts about lights.
There is such a thing as too much light. There's also a progression that you should follow going from stage to stage. There's a reason that the grow lights makers always seem to give a larger area for veg coverage and a smaller area for flower.
Let's say you have a 2 tent setup ... I for veg and 1 for flower. And let's assume that they're 80" tall.
For argument's sake, let's say you have a 4x4 flower tent with a 600 watt (at the wall) light. Don't care if it's HPS or LED it should be giving you 90-100K lumens. We can talk about PAR and PPF and PPFD later if you like, but for now let's keep it simple.
We're also going to ignore for the moment how high above the canopy you have your light. That gets to be critical in later stages of flower because light intensity decreases according to the inverse square of the distance. Simply put, you light's penetration power decrease very fast the higher off the canopy it gets. This is also a good argument for LEDs since they don't have the radiant heat issues of HPS systems and can get very close to the tops without damaging them.
So what this means is that when you have a full 4x4 level canopy (plant count is irrelevant), you will be able to use all of that light. In veg, you have nothing near that so at best you're wasting light and at worst you're damaging your plants.
So let's say in veg, you should go for a 400 watt (at the wall) setup. That's about half of the lumens of your 600w for flower. You bring your plants along from early veg at reduced intensity to late veg at max (440w) intensity, and then bring them to the flower tent at the same 400w initially, do your final training, and gradually bring up the lumens to 600w and decrease the distance until you're at max intensity and minimum distance.
So if you have a 600w 4x4 flower tent (which according to Goldilocks is "Just Right"), why would you want a 1000w 4x4 veg tent?
Rule of thumb for flower ... 3x3 450w ..... 4x4 600w .... 5x5 or 4x6 1000w
Go PATS
PS ... EVERY cheap LED maker lies. LEDs are great, but only if you have a great LED