Dual 400W or 600W?

[Gardengineer]

Alright ICMag, in my setup I've been running for about a year now, I have a 4ft wide, 5ft long, 6ft tall flowering room.... currently I can fit about 8-10 bushes vegged for about 2 months into the room in 2 gal. buckets.

I have a single 400w vertical ceramic metal hallide about 1/2 up the plants, and then a single vertical 400w HPS at about canopy level.

Question, would it be more effecient to trade in the dual 400 watters for a single 600w HPS and a 4ft parabolic hood, or another hood that will give good spread for the room size? I've had pretty good luck with my 400s, but if I could improve effeciency and cut down on power a little, I'd likely go that route. I know the CMH is supposed to promote good under growth and a fuller range of light all thru the plants life, and supposed to bump up resin production.

What do you think?

 

[EvilTwin]

Hi G,
I say keep the two 400watt lights. Looking just at square feet...your 20 sf should have almost 1000w. So you don't want to reduce your wattage.

Are you doing a proper Vertical grow? You could get horizontal reflectors and use the 400s in that configuration.
ET

 

[Gardengineer]

Not sure exactly how proper it is, but its been working the last 4 runs or so. What exactly do you mean by proper?

I thought of maybe using a parabolic hood on my top light so that all light (even being vertical bulbs) with basically be directed towards the plants, that way the top of my room with the ducting, filters, and everything else isn't sucking up light for no real reason.

 

[stonedar]

I can see very few scenarios where one 600 will outperform two 4's
that's my 2cents

 

[PkRipper]

along time ago i would stuff 3 large plants under two 400w hps aircooled ,in a 3 ft by 4 ft space. My only goal was for alot of really dense buds with no B.S. small stuff to trim or smoke on.

with that being the goal i heavly pruned and lollipoped all tha plants , and ended up with 17 oz of fine meds, the white widow alone had over 7 oz of really fat ass flowers,

the dude at my local hydro store pulls 17 off one single 400wt hps. but his flowers are not as large and has more trim leafs and are not as dense,........he just get more of but not as good as me.......we use the same food.

 

[statusquo]

I would go with more wattage... If you really have 20 sqft of space and only 600 watts, that is only 30 watts a square foot. A good medium is 45-55, obviously lower or higher would work but I feel over 60 is a waste of energy. Also keep in mind the light penetration will be better and more evenly distributed.

I would definitely run 2 400s - I am running 2 400W CMH for flower right now and am very pleased. Temps are a bit high so the yield is going to be impacted but its my first run so I am trying to handle one variable at a time.

 

[Big V]

I'm just gonna jump in on the bandwagon and say that you should stay with the two 400s. The CMH is a kick ass bulb and mor watts spread out more evenly has to be better. If you want to up your efficiancy then maybe consider a light rail. I use one in my veg and it covers a 4x5 platform very efficiantly with 400Ws.

 

[EvilTwin]

Not sure exactly how proper it is, but its been working the last 4 runs or so. What exactly do you mean by proper.

OK GE,
A vertical grow has a particular set of characteristics. Plants arranged in pots in a circle around a light. Either a cool tube or a wire cage surrounding the light with a fan blowing up toward light for cooling. And rotating the plants weekly to ensure budding on all sides.

Vertical grows are considered a high intensity grow and yields upward of 1 gm/watt are easily achieved.

Now merely dropping a lamp vertically into the middle of a large plant garden I would not consider to be a vertical grow.

The reason that mattered was that if you were doing two vertical grows with the 400s...then that would be an arguement for keeping things as they are. You'd lose that efficiency factor as well as wattage by going with a 600w.
ET

 

[Gardengineer]

This will give you a better idea of what I am doing... the plants in the room in the photos were from my 2nd run with it, I'm on my 4th/5th right now (perpetual). The HPS is normally lower, but I had it raised in the photos. I haven't needed the cage around the lights, I have a 4 ft tall piece of mesh in about a 12" diameter circle that fits around the lights nicely, but with a 10" fan blowing straight up toward my exhaust, a 10" fan blowing horizontally across the bulbs, and a large fan (24ish inches) cycling the air from outside of the rooms, a 6" inline fan pulling fresh air from outside, and a 6" fan cycling air from the veg room that dumps into the flowering room (for exhaust purposes), my babies don't get burned, even if they are too close, which I don't do... most are about 8"+ from the bulbs at the closest. Each light, obviously is individually adjustable.

Rotating the plants in a vert setup, however I don't do. In my personal opinion the plant wastes more energy twisting for the light rather than growing some gnarly dank... I pick the nicest side of the plant (biggest branches), label the container and focus the light on one side of the plant, the entire plant will lean one way after about 2 weeks (after stretch is done). I had guessed that the buds on the "unlit" side of the plant would be considerably smaller, but this isn't necessarily what I've found, since all branches will lean toward the light, they find open holes thru the canopy and still make a considerable amount, the branches that are always the closest I have make huge buds... in the end it probably doesn't even matter, 1 side of monster buds/one side of smaller buds vs. an entire plant full of moderate buds. I do however rotate the plants in the order that they are in the room.

 

[EvilTwin]

Hi GE,
I see the vertical grows are working out nicely for you. Why are you considering changing anyway? You just want to downsize?
ET

 

[Gardengineer]

ET, no, not really downsize, just thought I'd see if there was anything that was more bang for the buck so to speak. I've heard of a lot of people talk about 600w bulbs being more intense for their wattage versus a 1000w, kinda wanted to see if that was comparibly with the 400w vs 600w also. But if not, I'll stay with what I've got.

What about adding the 4ft parabolic for the upper bulb? That worth it... for as cheap as parabolics are, I thought to just wing one in there and see how it does. Only problem I see with this one is that I've had a few plants hit the 6' (ceiling) mark, with a parabolic on my one bulb I'd have to damn near move the entire unit to the ceiling to clear some of those larger plants. I dunno, maybe I don't need to fix something that isn't broken...

 

[EvilTwin]

GE,
Hey, nothing wrong with trying to improve a system. I've seen parabolic reflectors used very effectively with vertical grows. They are placed way high above the canopy like you suggested.

On the efficiency of the 600 over the 400...it is true that for the optimal lumens/watt...the 600 is best. But the efficiency factor is quite small over the 400.

One idea that I've been toying with is to use a vertical light mover. I have a light rail horizontal light mover and I would simply run a rope through a pulley which would bob the light up and down as the light mover goes back and forth. I could have a vertical grow off each end of the light mover. It's been done.

So there are ideas that could make your grow more efficient but nothing beats raw wattage of light...
Peace,
ET

 

[JustanotherDave]

I love parabolics for SOG.
And yes...I can see how a parabolic on top of a vert grow could only help.

 

[Gardengineer]

Only real problem I have found that introducing a 4ft parabolic would screw up a lot of my exhaust/air movement. I am sure if I get real bored, I'll design one to fit the room perfectly, get some plywood line it with mylar likely... I am about tempted to re-line all 3 of my rooms with mylar, I like the Panda, but I've noticed after time it gets brittle and tears a lot easier.

ET, good thought on using the light move to raise and lower the light, that never occured to me for whatever reason. Thanks for the tip.

 

[Green&Gold]

Hey Gardengineer

Can you tell me how far away your plants are from the 400WCMH when you place them in the vert? I'm trying to engineer a dual 400WCMH vertical and it seems my calculations for everything in the room, including the shelves, will depend on how far/close the plants need to be to the light. thanks