Feasible Combining Veg And Flowering Strips On Same Fixture?

[J.R.R.Toking]

Hi all,

I'm wondering if it is feasible combining flowering and veg light strips (like 4/3000k and 4/5000k) on the SAME fixture, and using the same driver (but NOT having both circuits connected at the same time)? I know that many believe there's one temp (like 3000k or 3500k) that is fine for both stages of plant development, but other, very experienced growers are adamant about the definite advantage of using cooler spectrum lights for vegetative cycles to increase speed between cycles (Think how many growers SWEAR by metal halide for veg cycles, not just simply for speed, but for internode sites and plant health/bushiness...I.E.: ScrOG.). Honestly, if it could shave even 7-10 days off the time between going veg to 12/12, and assist stretchy strains to remain a bit more compact, it would more than cover the cost and labor involved in mounting 4 additional strips on the same fixture in a flower room.

I am CERTAIN there's a more elegant way to accomplish this switch (like with some kind of toggle switch), but a brute-force way I envision constructing/wiring the light fixture is, for example, in the 4'x4' F-Series light using the LT-FB24B 4′ LED Strips, make the Angle Aluminum frame just big enough to fit one additional strip/heatsink on one end, then after the 4-3000k strips are spaced-out/mounted, mount the 4-5000k strips ALTERNATING between these flowering strips. Do your normal parallel circuit for the flowering cycle and wire it up to your HLG-480H-48A, and flower out your plants as usual. Also, have a SEPARATE parallel circuit wired-up with Wagos for your 4-5000k lamps, and tie it off (unconnected)until it's time to use the space for another veg cycle. After the flowering's complete, simply disconnect the Driver wires from the "flower" circuit, and connect it to the "veg" circuit...simple and quick. Not everyone has the space available to have a completely separate veg, and this would be an easy way to utilize the same space with maximum result. Probably not worth if for a few extra ounces of tomatoes, but...

The main question is to figure out is what's the minimum number of veg-cycle strips that would need to be installed to be able to utilize the HLG-480H-48A safely in this example, so as to NOT BLOW/OVERPOWER the 5000k strips? Even though you don't need the same intensity of light to get good vegetative growth, you don't want to have to buy another driver in this scenario...so would using a Constant Voltage driver be the solution, or is it better to just add the minimum number of 5000k strips so as to power this original (Constant Current) A driver in a safe manner? Using 4 of the 4' LT-FB24Bs for flower (as-in LED-G's 4'x4' Example Build), I believe using the same driver to safely fire-up the veg 5000k strips there would need to be at least 3 of the 4' LT-FB24Bs hooked-up (or else you could blow the strips at full power). So, would dimming the driver to say 50% allow you to use just 2 of the 5000k strips?

I hope I'm articulating this post, but it's late. What color temperature is best for vegetative growth in the F-Series...5000k?
Also, is there an "elegant" inexpensive solution to installing a toggled switch box in this fixture? It's really not necessary, however, as switching the lights back and forth would only occur maybe 5-7 times per year...not enough to sweat an expensive, involved wired-switch solution, but still enough grow time to warrant adding the vegetative strips to this fixture, IMAO.

What do you think?

[Grower]

What a long post!
Btw I would go for 2 different drivers, way less hassle.

[majorana]

Just have the DC side of the driver connect with a wago (or anything similar of the sort). Attach all veg strips (5K) for the month of veg, and then "unplug" that and replace it with the flower strips (3K) for the next two months. I'm not sure what the issue is, I'm pretty much rephrasing your words.

If you grow more than one cycle at a time it could be a good idea to separate the two, in two different spaces. That way you can have month-old veg plants ready to get in the flower space the moment those are done. Of course the first time I did that I forgot that I should also calculate a week of drying in darkness (and in an odor-controlled space.)

[J.R.R.Toking]

What a long post!
Btw I would go for 2 different drivers, way less hassle.

I get paid by the word.

[J.R.R.Toking]

...I'm not sure what the issue is, I'm pretty much rephrasing your words....

I guess I'm looking at two things; what settings I would need on the HLG-480H-48A (onboard dimming pots) to support a minimum/maximum amount of vegetation strips (how many, and what type) for the space (4'x3'). Yes, I need to work on my LED calculations/equations to this this stuff out for myself. HPS lamps, while inefficient, were pretty straightforward.

And while yes, I know the advantages of having a separate veg space, every extra cab exponentially lowers your chances of keeping things stealth.

[majorana]

I guess I'm looking at two things; what settings I would need on the HLG-480H-48A (onboard dimming pots) to support a minimum/maximum amount of vegetation strips (how many, and what type) for the space (4'x3'). Yes, I need to work on my LED calculations/equations to this this stuff out for myself. HPS lamps, while inefficient, were pretty straightforward.

And while yes, I know the advantages of having a separate veg space, every extra cab exponentially lowers your chances of keeping things stealth.

In a 4*3 you'd want approximately 420W of light and 1100-1400 diodes for flower. For veg you can work with half as much. The driver can easily take care of that, and the number of strips and how to wire them would depend on what you buy. Have a look here: http://ledgardener.com/diy-led-strip-bu ... bridgelux/

As for keeping things stealth, that would vary widely from situation to situation. If an extra veg tent is a liability then simply go with one crop cycle at a time. Where I'm at the biggest problem is odor control, and in consequence the noise emitted by the negative-pressure ventilation system (which isn't necessary in the veg tent.)

[J.R.R.Toking]

Well, so I ordered 4 of the 4'-288 diode strips in 3000k, and 2 of the 4'-288 diode strips in 5000k. I have some lead time to kill, so I'll see if I want to mount these to the same fixture or just get another driver...but I'm leaning towards the former.

Either way, I'll use nuts and bolts to secure all strips/heatsinks to the frame instead of pop-riveting them, in case I want to rearrange or separate the strips for different positions/fixtures in the future.

Using the HLG-480H-48A driver, how, specifically, would I want to run the 2 veg strips so as to not damage them from the driver?