mixing some 6500k cfl's around the sides of a 250 watt 6000k metal halide

[Rum Nugginz]

I am using a 250 watt 6000k metal halide in a 2x2 tent for some seedlings and plan on vegging them in there until it's time to flip em. I am using two 23 watt 6500k cfl's on Y splitters on each side of the metal halide reflector, adding approx. 100 more watts (92 watts) Doesn't it make more sense to hang the cfl's at the same distance above the canopy as the mh bulb, so that the 2 spectrums overlap and intensify, instead of hanging them lower along the sides of the plants? From what I have noticed, it seems that the plants benefit mostly from stronger light that is directly above them as opposed to side lighting, where 1 or 2 branches might get a little bit of supplemental light, as opposed to concentrating all of the light directly above the canopy? By focusing it all above the canopy it will basically in a sense turn the 250 watt light in to 342 watts of intensity. Just wondering what some of you think about this. I think the extra lumens will be best utilized above the canopy as apposed to the sides.

 

[Darkoh69]

I think the 250mh is more than enough to veg some seedlings in a 2x2 tent. Put the cfls in the bin & put the time & effort you save into something else. But you’ll probably run em both together anyways do to get to the root of you question. If you run the cfls at the same distance from the canopy as the MH lets say 10 inches, which is the closest you’d want to put a 250wMH to the top of your plants, this would be more than double the ideal distance from canopy of the cfl. Put simply if a 26w CFL was hung 10 inches above the canopy the tops of your plants will only see 1/4 of the ‘claimed’ light output they would get if the light was 4 inches from the plant.

 

[WubbaLubbaDubDub]

I think this @Darkoh69 is right. It’s 62.5watts per sq ft with your 250. That’s plenty for now.

Are you going to flower in the tent too?
Work on all the other important things in the tent like stable day and night temps,controlled humidity for veg/flower, airflow in the tent,adequate intake/exhaust.

I’d say start your seeds with the CFL’s and veg then remove the CFLs and flower with the 250

 

[Darkoh69]

I think this @Darkoh69 is right. It’s 62.5watts per sq ft with your 250. That’s plenty for now.

Are you going to flower in the tent too?
Work on all the other important things in the tent like stable day and night temps,controlled humidity for veg/flower, airflow in the tent,adequate intake/exhaust.

I’d say start your seeds with the CFL’s and veg then remove the CFLs and flower with the 250

Yep cfl perfect for germinating-250mh not so much

 

[WubbaLubbaDubDub]

Yep cfl perfect for germinating-250mh not so much

Well you totally can it’s just a waste energy and you keep it so far away.

 

[Rum Nugginz]

The idea is not so much penetration into the canopy but more of changing the overall light spectrum that is being cast down and around the tent, bouncing off of the walls and hitting the top of the canopy. By hanging them at the same height, or about 1/3 down from it, the 2 spectrums overlap. I do normally start my seeds with 6500k cfl's as I have about 20+ of the 6500k cfl's in different sizes ranging from 23 watts up to 65 watts. I usually make a 4 way splitter and hang that over them, then add more Y splitters along the sides of that. I have been using CFL'S for over a decade for this purpose and I agree 100% that they do work great for germination and veg but the problem is all of the cords that have to be tied up and out of the way. And when the plants really start to take off growing, the lights have to be adjusted every day etc. Not to mention it becomes a safety hazard with all of the bulbs in there. It is a much neater, simpler operation with just the one cord from metal halide reflector and a Y splitter neatly hung on each side of that. I normally hammer them with over 400 true watts of cfl for about 1.5 months before I move them into the taller flowering tent with either the 400 or the 600 watt HPS, (depending on how tall they get). I just recently started using the metal halide for veg and I agree that it is probably enough for the seedlings, but will need supplementation once they get bigger. At the moment I am supplementing the 250 watt metal halide with four 40 watt cfl's bringing the total true wattage to 410 Thanks for the replies I appreciate the help.

 

[Rum Nugginz]

Like I had previously mentioned, I have normally always used cfl bulbs for seedlings and veg, this is the first time using the Metal Halide for seedling/veg stage. I have to agree that even just the 250 watt MH bulb in a 4 sided reflector provides plenty of light for full veg. The intensity is so much more powerful compared to cfl's of the same wattage. There is really no need to use the supplemental cfl's at least until the last week of veg, when I might add the 2700k bulbs back for the transition, to acclimate them to the new spectrum. Heat is also an issue even with the 250 watt. I have raised the reflector and it has helped bring the temps into 76-78 degree range. The footprint from the reflector in the 2x2 tent is incredible after raising it up a bit higher. I think that keeping it too close, does more harm than good. Thanks for the replies, One of things that I love about this hobby is that you are always learning something new every day. Environment is key and cannot be overlooked.