Very simple question to get me started on a diy led

CobKits said:

id like to see some 2 gpw gardens. havent seen one documented yet. im not saying its not doable but it would normally entail longer veg time, lots of topping and training, lower PPFD, in conjunction with very efficient lights and a good grower. often times gpw is at the expense of g/SF so your criteria may be different

vero "C" is a voltage model not a bin. it is the most expensive of the veros, and whether or not you get value out of that depends on how hard you run them. at lower wattages the difference between the vero C and chips that cost half as much are subtle, less than 1%. The bigger chips are generally indicated if running above 75W per chip, which may not be in your plan if high gpw is your criteria

you can do the same thing with larger chips (Vero29, citi 1825, etc) with smaller chips (citi 1212, luminus cxm22), if you have an efficiency target for a given chip you just need to run each chip softer and use more of them. checkout @DesertHydro posts for some great results with the smaller chips.

hard to make recs without knowing your space size.

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Thanks for the reply.
Okay so I did not know that driving chips harder would work against a high gpw, I'm just looking for (like most other people) more yield. Also I don't know how much more growing i will do after this because I'm not in a legal state, but I atleast know that I want to try one more run. So taking that into account, if the yield difference is going to be minimal off just one grow, no matter what cobs I use, then obviously I wouldn't need to go all out on the top most efficient stuff. However either way I'm willing to pay a little extra to make sure I'm not skimping on any light and have plenty of cobs.

My grow area I haven't completely decided on yet. Its either going to be inside my 5x5 tent again or I'm going to make it a 4(or5)x9 inside of my 9.5x9 room.

So given that, what would your recommendation be?

NugHeuser said:

I'm just looking for (like most other people) more yield.

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more per watt?
more per square foot?
more per plant?

NugHeuser said:

So given that, what would your recommendation be?

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its hard to recommend spending thousands of dollars on some uber-efficient setup you may only use once. a cheaper HPS or CMH would fit the bill here. it takes time to payback an LED setup. it takes even more time to payback an uber-efficient LED setup

You will always get better yields with experience in running the same strain over and over to find the ultimate environment. Then 2 gpw may be achievable. The is no magic light that instantly will give you 2gpw.

CobKits said:

more per watt?
more per square foot?
more per plant?


its hard to recommend spending thousands of dollars on some uber-efficient setup you may only use once. a cheaper HPS or CMH would fit the bill here. it takes time to payback an LED setup. it takes even more time to payback an uber-efficient LED setup

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Okay I see. So I guess what it boils down to is I'd like more yield per SqFt. Also I'd like to not have to worry about heat issues, mainly only a problem if I stick with growing in my tent. So basically it would be pointless to spend more bucks on the fanciest most efficient cobs since I don't know how often I would use the setup. But if I decide to use my tent again I want to go led, if I used the bigger 9x9 room I may just go with more hps.
So for my 5x5x7 what cobs and how many would you recommend?

id go with an ACDE air cooled DE HPS hood at 45-50W/SF for now.

would give you excellent g/SF and the vented hood will work great with your tent

NugHeuser said:

Also I don't know how much more growing i will do after this because I'm not in a legal state, but I atleast know that I want to try one more run.

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zypheruk said:

You will always get better yields with experience in running the same strain over and over to find the ultimate environment. Then 2 gpw may be achievable. The is no magic light that instantly will give you 2gpw.

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Growmau5 has gotten close. I think it was just over 1.9.

I've managed almost 1.7 including popcorn, in hydro. It's impressive when considering that it was using Vero29g5 at 700ma, what I estimate to be 42% efficient. And the g/sqft was 59... that was achieved with a PPFD around 780 (350w output using said emitters/current in a 10sq/ft area, 3000K 80CRI).

I think the equipment already exists to hit 2 GPW. How to do it?

Grow in hydro and keep the lamps output efficiency over 50%, preferably closer to 60. PPFD will ideally be under 1000 but I don't think it needs to be some seriously low number like 600. 800 would probably work fine.

The lamp itself will provide optimal par readings at a very specific distance. An inch to high or to low and efficacy starts to drop. Use a cheap light meter and notice how the ratio changes, inner readings vs outer readings at various distances. You can also do a hand test, moving your hand towards the emitter until it starts to look bleached. You might be surprised how close you can get plants. With higher power cobs some distance is necessary to get full coverage, but if you're running an array of low power cobs get them down on the plant like they were fluorescent bulbs.

Also, if you're using low power emitters and getting them close, might as well ditch the reflectors.

That's all I can think of. There are other things to boost yield but it's all general stuff. 2 GPW will happen... and it will be LED that does it.

Another way to examine the equation is with grams per par watt. I've calculated several DE HPS grow yields, one of which was running flood tables. 3 600w DEs, 42% efficient light source by output and the yield came out to about 3.5 grams per par watt. We can use those efficiency figures to estimate the efficiency necessary to achieve 2 GPW under similar conditions.

For instance, a 200w 50% efficient lamp from the wall provides 100 PAR watts. 100* 3.5 = 350 grams / 200 = 1.75 GPW. A 200w 60% efficient lamp would provide 120 PAR watts. 120 * 3.5 = 420 grams / 200 = 2.1 GPW. It's not that simple of course, many other parameters and hydro is probably necessary, but there's no logical reason to assume 2+GPW is out of reach.

BTW, plucking the popcorn bud out of my example, comes out to about 3.5 GPPW which was also 1.5 GPW, same as the DE example. Both around 42% efficient, so the concept does translate from one light source to another. There are theoretical reasons I don't put much stock in spectrum making major differences in yield, but there are also real world examples like that which illuminate the reality that PAR wattage matters.

Building a 60% efficient from the wall lamp is another matter. It would require Vero29C at around 25 watts each, or CLU058-1825 at 33 watts each, or something similar. Most people aren't crazy enough to do that.