Hey guys I got two seeds I've been germinating and they ready to plant 1maui waui 1white widow.do u guys recommend I use a 400watt hps light to use on my seeds?i don't got no other option..my last grow was stretching so I had to put her down!!!how far should i keep the light.from the plant I'm Tryn to avoid stretching
400 watt hps for seedlings
- Thread starter Dustgxf
- Start date
dimebong
Well-Known Member
HPS bulbs have a harsh and limited light spectrum concentrated in the far red. You'd get more stretch using an HPS than you would a 23w cfl 1 inch away considering the distance you'd have to keep it from bleaching. It's also a huge waste of power keeping a 400w on for at least 18 hours as the seedling wouldn't even be able to use all that light if it were emitting blue.
It would work with stretching but a cfl would be better, then you can use the HPS for veg if you want but it's a waste.
It would work with stretching but a cfl would be better, then you can use the HPS for veg if you want but it's a waste.
dimebong
Well-Known Member
I veg 24/0, you can pick whatever veg time you want over 18 hours.
I keep 1-3 23w cfl's on any clones/seedlings i'm doing until their stem starts thickening out then they go under an HPS with 30% more blue spectrum for 12 hours a day and back under the cfl's as i'm usually flowering when i start anymore plants.
I'd preferably be vegging under t5's.
Inter nodal spacing is pretty good with the lights i use. Growth rate is slower than i'd like.
sonar
Well-Known Member
How many weeks veg are those plants in that picture? I use a 2' 4 bulb 6500K t5 for veg and that uses about 100w by itself. They are kind of expensive for what they are, but I could have gotten one twice that size for just a little more but that was all the room I had at the time. It's great for a couple weeks but I feel like after that I would be better off just going to the 400MH. Lumatek ballasts are more expensive but worth it in situations like that where you can keep the same 400w bulb and dim it to 250w to save a little on power and less heat.
That's funny you mention you think your cfl's are slow. I always thought my t5's were a little slow.
That's funny you mention you think your cfl's are slow. I always thought my t5's were a little slow.
mr2shim
Well-Known Member
HPS lights cause stretching with seedlings not MH. I've used metal halide for veg for years, never ever had one plant "stretch" They're always short and bushy.
The design of the light has nothing to do with the way a plant grows. The type of light the lamp emits has everything to do with the way it grows. To say an HID light causes a plant to stretch is foolish.
mr2shim
Well-Known Member
My light is always at the top of the tent. You can look at my grow if you want. It's in my signature. I grow from seed under HID. Metal Halide for seedling/veg stage then HPS for flower, which causes plants to stretch.
*When there is little available light a plant will always stretch. That's just common sense, wait no it isn't. Sense is no longer common.
prosperian
Well-Known Member
I use a 400w MH for seedlings through veg. Absolutely zero stretch. Listen to mr2shim on this.
I would not use a HPS or MH for young plants (seedlings)..as 1. The plants will not even use that much light.( so a lot will get wasted) 2. You will have to keep them far away or they will just get heat stressed easily...once you move them far away to avoid heat stress..the Lumens will not reach the plant 100%.
Get some CFL's or Floros to start them off..then switch to HPS or MH once they are a bit older.
Get some CFL's or Floros to start them off..then switch to HPS or MH once they are a bit older.
mr2shim
Well-Known Member
My grows disprove everything you just said.
prosperian
Well-Known Member
I don't understand why some peeps recommend buying more stuff when what they have will do an excellent job if used correctly. For those worried about cost savings while running a HID 400w mh for five extra days? C'mon that's your argument to go spend more money on cfl bulbs and fixtures? Keep it simple fellas and learn how to use your equipment.
mr2shim
Well-Known Member
Power here is .10 cents per kw/hr
5 extra days of running a 400w is.....
400w x 18 hours a day = 7200 watts or 7.2 killowatts
7.2 kilowatts x .10c per = .72 cents a day
.72 cents a day x 5 days = $3.60
About the cost of buying one 23W CFL bulb. Conclusion, everyone who says that you're wasting energy and buy CFL bulbs in the mean time is an idiot that fails at basic math.
dimebong
Well-Known Member
They were cut in late December and took about 2 weeks to root. The growth rate is fuckin painful in a flowering setup with 2 cfl's and an HPS.
I might look into a 250w mH. I'm really just thinking about power usage as i'm not a seller.
bullwinkle60
Well-Known Member
I use my 400 watt MH for vegging with excellent results. Then when I switch to 12/12 I use a 400 watt hps. Happy growing.
