Different ballast driven lighting questions

Hi Guys,

Thx so much for helping me in my journey's.

Now i have a simple question, Does a higher wattage bulb (CMH, MH or HPS) make a plant veg/grow faster? If i have 2 plants, one under a 250w and one under a 600w in ideal comparative circumstances, after 2 weeks, will both plants be the same size, give or take?

Cabinet 1: 250watt Ceramic MH. DWC system, Canna Aqua line up on the nutes including the ALL the Canna additives. 500 CFM cooling, 28 celcius radiant temps @ 5 inches, 22 celcius ambient.
Cabient 2: Solistek 600W/400W ballast with 600W cooltube HPS dimmed to 400watt w/ solis boost. RDWC system for vegging/flowering, same deal on the nutes as above, more cooling in this one.

If both plants are initially 1 inch tall, shouldn't they both grow at more or less the same rate, until 8 inches tall, where the the plant under the larger bulb will out grow the smaller one.
As per this foot-candle chart ( http://forums.cannabisculture.com/forums/uploads/1063932-Foot-Candles MH Done Now.jpg ), shouldn't the light received be sufficient for equal rate growth on the 2 plants. They should grow the same rate until the smaller bulb cannot compete with the larger one for overall penetration?

Now obviously when your flowering, the effect of bulb intensity is screamingly obvious. Light is only emitted a certain distance from a bulb, governed by its power output, but is this light equally as powerful for growth?

I hope my stoned brain has communicated my question clearly enough...

Im contemplating a 8-10 site vertical grow around the 250w CMH instead of the 2 site currently under it. I would convert the new 600W cooltube setup to vertical but im addicted to RDWC/SCROG, veg for 6 weeks and LST through a screen, then flip it and add 6 x 32W CFL's under the canopy. The new cabinet has a 250W CMH, any suggestions aside from vertical for maximising light distribution?




Thx Guys.

In the early few days of a plant getting roots then it is not advisable to add a ton of HID light. After the roots have been established and the plant is ready to go then yes - more light will produce faster and bigger results. Dont forget to get the root mass as big and healthy as possible as soon as possible and all through out the grow. It plays a big factor in the growth rate of the plant.

Cool, I thought being a 250watt, I could get away with it being closer. I should expect relatively equal growth for the first few weeks of veg? (250w CMH vs 400w HPS), I know the internode distance will be different slightly, but expectation for overall growth?

Ive never had an issue with root mass, normally fill a 52L tub with dense roots. God bless Rhizotonic+Cannazyme combo... Aqua+Rhizo+Cannazyme= Holy Trinity of Root mass. Im just irritated with the growth on my new 250w CMH, My 40w CFL for cloning is out growing my 250w

Although the new plant (250w) has not completely established yet, it has new growth and has grown 2 cm. Not even out of its first week yet, Normally it takes 3 days, and I have explosive growth... I didnt think the 250W was slower than a 400/600W, Just didnt grow as tall or bushy...

Can someone PLEASE help and clarify for me...

I believe in perfect conditions the plant will grow geometrically larger based on what it can take in. There is a limit on the amount of light a plant can assimilate. 600 is not the limit but it could be argued that depending on the distance from the leaves you might be able to reach the limit but I believe that that distance would produce too much heat for the plant to survive. -> https://www.rollitup.org/grow-room-design-setup/101350-max-lumens-before-growth-rate.html

Respect.

That is exactly the information i desired.

So using that information we have established the following;

MAX GROWTH RATE = 10,000 lumens is MAX USABLE light per foot square. Or worded differently, 10,000 lumens per 0.1 metre sqaure. (one tenth of a metre square)

The chart i linked above outlines lumens per inch of depth from the lights source. Now @ 10,000 lumens, A 400w Bulb supports 15 inches of plant height at MAX GROWTH RATE, where as on the other hand, A 250W supports only 11 inches of maximum growth rate.

My question is, Should both plants grow at the same rate of height and width until they start to outgrow the available light. ie 10,000 lumens mark due to radiant bulb heat. etc etc

I think what happens is when the plant is young, it produces new leaves and stems and nodes. The first leaves are close to the main stalk. When the plant gets bigger the stems stretch out the branches start to create more leaves on the branch and the foliage on the outside gets more light than the leaves closer to the stalk - because the bigger outer leaves are blocking the light to the interior leaves. There is a height limitation based on the strain that is usually pretty easy to find on the net.

To answer your question, are the lights at the same distance from the plant or is the 250 closer? -> http://www.google.com/url?sa=i&source=images&cd=&cad=rja&docid=0lf2TSnXddJ5HM&tbnid=yOoxv6KAivzQKM:&ved=&url=http://www.420magazine.com/forums/problems-pests-disease-control/54116-agrosun-hortilux-whole-way.html&ei=7B0HUvhYybzbBfTtgZAK&psig=AFQjCNGMQKQbc02_gmPu1JC8S-X4SDWkvQ&ust=1376284524102050

Yeah that answers my questions, Thats the same chart i linked above. The plant under the new 250w CMH has only little new growth, but explosive root growth. Its acting odd, I would normally have explosive upwards growth by now as well as the root exploding downwards. I shall re-examine my soup, I think my nutes are a touch high.

But to clarify, a 250W full spectrum Ceramic metal halide light will grow the usual 1cm a day under 24 hour light? DWC.

Thx man.