# grams per watt

Discussion in 'Indoor Marijuana Growing' started by lance, Apr 24, 2006.

1. what are ur absolute best chances for growing two to two point five grams per watt with a soil grow? do not calculate my watts...they are irrelevant. whats the strategy? is it veg time? the size of the finish container? genetics? light movers? the grower himeself of course plays a part, yes, but given big bud crosses, money, time, creativity, patience, how could one gain the most? im not thinking hydro. not yet.

2. im not 100%, but i think its pretty dam near impossible to get 2.5g/w...but agani not 100%...
i guess if you veg it for a shit load of time and get a massive plant then it will increase the yeild...

3. I don't understand why that is irrelevant. I doubt there is an easy way to project grams per watt (way too many variables, plus difficult to impossible to measure them all), but even if there were such a formula your statement presumes that it would be linear in its output regardless of gross wattage used.

For sake of argument, let's say that there can be derived a formula (again, which I highly doubt) that says that a 400w light used with all other conditions ideal would yield 600 grams. That doesn't mean that you can just divide both sides of the equation by the same number and the formula still works -- using a 1 watt light won't generate 1.5 grams of quality bud, it will produce a dead plant real fast.

The yield potential has a "sweet spot" of lumens (of the right frequency) per whatever (usually thought of as wattage per square foot), such that the per-unit yield will be lower at both below and above that sweet spot. Put more simply, there is a rule of thumb that says something in the neighborhood of 50-70 watts per square foot is the sweet spot. Using less will deprive your plant and hurt yield but using more could cause lumen burn and/or cause your plants to channel their energies into less-than-maximizing efforts.

Having said all that, it makes sense that one would reach the maximum potential, whatever it is, by maximizing every single variable, so why not strive for that? Underlying your question seems to be the idea that perhaps you don't have to worry about factor X too much as long as you work hard at factor Y. I think the more realistic way to look at it is that all the factors are links in a chain, and the chain is only as strong as its weakest link -- so lower-quality input on any factor, whether soil, lighting, genetics, ferts, timing, etc, will hurt the final yield.

4. hey guys,

i think toasty has it mostly right. i did wanna mention that lumens are much less significant than watts, due to the fact that lumens are based on a 1' distance from the light source. if say you've got a 1000w bulb on a small room/closet, you cant take its initial lumen output/sqft and say your plants are getting "x" lumens. other than that, i believe you've gotta optimize all the parts to get the whole. lets look at the actual process, and see what happens when something off... im going to talk about my hydro setup...

nutes - ppm in the water. ok, they're present for the plant to take, if they want it. too much and she will uptake too rich a solution and shell burn. too little and she wont be able to build new plant parts for producing branches, leaves, or buds. to optimize is to not under feed her, which is to not allow her to grow to her potential, and not over feed her where she burns - ouch! you really cant MAKE HER produce better buds with more nutes. shes more bound by genetics

pH - ok, nutes are in the water... the roots are in the water, now how are they gonna get the ntues??? well, roots have many semi-permeable cell layers that allow water to seep in or out... the plants are like a spounge sucking up water and evaporating it out. pH only allows the nutes parts (the N, Mg, etc.) to pass through the semi-permeable barriers (roots) and to our plant. a bad pH doesn't allow our plant to drink. thus she drinks water, but the nutes are unable to be absorbed and sit in the bucket. ppm goes up. overall, pH cannot produce bigger buds than genetics allows

light - the energy your plant gets. more light is more energy for your plant, so she will absorb more nutes cause shes more active (like you eating cause you worked out). its like light + nutes = building blocks of plant... more of each (starting with light) equals bigger plants and bigger buds.

thats a HIGH rant rather than my scientific discoveries. just lots of reading... peace ya'all

5. Thanks Red. FYI, when I mention lumens I am referring to the amount of light that the plant is actually getting, not the way that a bulb is rated. So watts is electricity consumption, rated lumens is some sort of standard basis for comparing bulbs, and actual lumens are what your plant receives as measured by a light meter put right next to it.

6. Don't forget to mention the differences in bulbs when it comes down too lumen/watt and proximity to the light source.

You cannot get a plant close to HPS or MH as we all should know.
But with fluro's, especially the tubes types not the spirals you can allmost stick the plant inside the tube because it does not get hot.

(just make sure you put the tubes in observing correct polarity!!! or else the tube's ballast is gonna get cooked (but the tubes do appear to work normally FOR YOUR EYE thats the culprit here) : ESPECIALLY TRUE with multile fluro's in close proximity.

If you connect 2 fluro's next to each other in opposite polarity, the electric fields the tubes produce will put the brakes on each other = far less light & far more heat)

7. hey guys,

so um.. your post on polarity got me off my arse to ask you about my lights... i used to hang each by its own chord, they were about 1/2' away from eachother. when i sparked up this new grow, and couldn't hang the other chord so i put them back to back. i have a screw-hook now, so i could change em, but if this is ok ill stick that this.

also, its tough to get the HPS close, but it can be done peace ya'all

Relax man! Have a schmoke.

You safe all the way with them spiral fluro's.
With polarity I am reffering to electric polarity + and -

Your spiral fluro bulbs screw into a socket. It only has 2 seperate electric connections you can mess with. Its safe to assume that that fixture's internal wiring is done properly. Also, with close proximity I mean less then 2"-4" depending on the tubes power.

With tubes (e.g. 2 foot long 18W) you have 4 pins per tube. + and - on both sides of the tubes. The tubes are symmetrical all the way so you can insert the tube 2 ways into its sockets. The way you stick in the tube wil determine (depending on the incoming phase from your 110V or 220V connection at a moment in time) in which direction the electric discharge will take place = electric current. This will produce a electric field and a magnetic field in opposite directions. If you add a second tube too close which runs in the opposite direction (wrong polarity) the positive electric field from 1 tube will ENHANCE the negative electric field from the other tube. Same goes for the magnetic field.

Like two magnets pulling each other with opposite magnetic poles.
Like when you put your ash tray really close to a CRT computer screen and use it you will see the ashes fly up to the screen because they have opposite electric charge.

The ballast that comes with the tube are supposed to absorb excess energy even in a single tube situation. When the anode and kathode are electrified the mercury evaporates and discharges electrons into the tube which in turn lower the electric resistance between both sides of the tube which means more power will rune through it. Without a ballast the process will runaway and auto-destruct the tube.

So normally the ballast is the brakes. If magnetic and electric fields of tubes enhance each other because the tubes are in opposite polarity the runaway process will pick up speed. So you need more brakes = ballast. This is exactly why they (the ballasts) get too hot.

This is where things go sour.

Check the picture I included to see what the inside of a fluor tube looks like.

And uhhh O yeah : I have got to say I like your plants dude. They look nice and healthy. We would all love to help you smoke those babes ! Good luck flowering and nicely done with the HPS in a tube.

9. oooo, thanks for clearing that up. i got all paranoid, but now its all good peace

10. Its a useful aproach that of g/watt, although may be unrealistic.

In my case, asuming i get a 50 g yield with my system, im pretty damn sure that the next crop will have some changes in order to get some more that 50 g. Evidently there will be a physical limit, but its certainly a good sign wanting to maximize yields.

Currently on my first grow
4x39 daylight Osram Fluoros hung up in chains, some old school twist, jeje.
4 Indicas
6 Sativas
.5 g/L of "triple 17 plus" (17-17-17 N-P-K and some micrconutes)
.5 g/L of "nutriflor" (15-30-15 N-P-K)
35 days 12-12

11. urgr8estfear,

are you shit'n me? all these years I never knew that I could be putting these things in backwards? so is one end - and one end +? or, is one pin on each end the neg and the pos?

12. Did you check the picture I posted?
I guess NOT!

It clearly show 2 pins ON EACH SIDE of the tube. Totalling 4 pins PER TUBE.
For the type of fluro I posted, this is absolutely true!

So no I'm not shitting you.

13. yes, I did look at the pic. Did you? You will note that your pic does not label which pins are positive or negative. Being that I am pretty familiar with a fluorescent tube (and not mentally handicapped) I am well aware that there are 2 pins per end.

My question, again, is: Is ONE END of the tube the negative side and the OTHER END of the tube the positive side?

or...

is ONE PIN on each side positive and ONE PIN on each side negative? <-- meaning EACH SIDE has a negative and positive pin on it.

14. LOL.
Funny guy.
I'm not going into that mentally handicapped shit but :

The picture does indicate polarity. You just don't recognize it.
Check the dictionary for the word 'cathode'.

I guess you could look at a tube as if it 2 incadescent bulbs-elements in 1 glass bulb.
Only then someone made sure there is a polarity and potential difference between both bulbs.
Like 1 bulb gets 0-110 volt and the other 1100-1210 volts.

15. I am well aware of what a cathode and anode is. In your picture, it denotes a cathode and has a specific shape. On the other end is the same shape and it is not labelled as an anode, so I would be inclined to assume that it is, also, a cathode.

Also, I would like to point out that I've never purchased a fluorescent tube that had a cutway view and a label saying "this end is the cathode".

Could you just answer my question? If you don't know, it's OK to just say "I don't know".

16. OK. I simpe as I can explain it:

2 pins each of the tube, both a positive and a negative.
The other side is its mirror image.
So you got - and + on one side, + and - on the other.
The cathode (one side of the tube) and anode (its mirror image) alternate.

You got that?

17. You could call both sides of the tubes a cathode.
Only then one cathode would be a whole lot more negative then the other side.
That's why I prefer to call it anode, else you would ask me why there is energy transfer from cathode to cathode.

The wires in your power outlet are not + and -.
One is phase (brown) and the other is null (blue).
One alternates between -220/-110 and +220/+110 and the other is 0.

So for the tubes, there really isn't a + and - either. Just in relation to each other.

And what on earth is a douchebag anyway?

18. perfect. that's exactly what I was asking. Each PIN on the left side is + and the other -. Each pin on the right end is a - and a +.

So, now that we have that sorted, back to waht you were saying: when you place these into a shoplight fixture (let's assume it holds two bulbs), you want to make sure each cathode is next to each other and each anode is next to each other correct?

19. Litterally, or slang?

20. Uhhhhh,

Theory:

This + and - stuff is to help you and others understand.
In reality, there are no - and + pins.
This is AC power. Alternating current also imples alternating voltage, since the resistance can't go negative.(V=IR)
Only null on one pin(wire) and phase -X volts to +X volts on the other.
Tubes with this issue (non-CFL) have a marking on one side of the tube.
On both sides of the tubes there are round metal parts to seal off the glass airtight.
On one side of these metal parts there is a little dent in the metal which seems to serve no electrical or mechanical purpose.
This 'dent' is there for you.
This 'dent' is suppose to face outwards so you see it when mounting the tubes.
If you do so, both tubes will have proper polarity.

Practice:

Dent outwards : GOOD!!!