Light query


#1

I have 150 watt high pressure sodium light thinking at the time with a small 2.5 ft x 2.5 x 4.5 ft grow space that it would be enough. I know now it’s not so I just ordered another of the same to get more light to the plants. The plant that is up is doing well in the sense that it is healthy and growing albeit it seems slowly. I believe it’s just under a month old now and was wondering if it could be the low wattage or is it the lamp itself? It is a grow light so there’s that, but will the next light help or was I being dumb and should have gotten a better system? I have another question in another thread with a pic but I’ll add the same pic here to see what you think. Thanks for any help you can offer.
P.S. What are your thoughts on sodium lights for growing? Thanks again


#2

PLants grow slowly. Be patient! :mrgreen:


#3

I have another question Latewood. I bought another light, a florecent grow light, thinking that it was a bright white one and found out after plugging it in it’s more purple in color. Could you tell me if this is a good light for the vegetative stage or not? I was thinking in terms of the blue spectrum I’d heard about. The reason I didn’t get the blue light you’d suggested was it was only 10 bucks at Walmart. Thanks again in advance for any help.


#4

I would look on ebay and find a grow bulb that fits the lamp you bought.


#5

If you mean it is the:

Lights of America 24" Fluorescent Grow Light Fixture:
Quick on/off switch
5’ plug-in cord set
75W of incandescent equivalent output using only 17W of energy
Save 78 percent on your utility bills
Color: 4200K
Lumens: 1093
Dimensions: 2.5"W x 2"D x 28"H
Life: 10,000 hours

Then it is a very weak light, any full spectrum 24" T8 will fit in it, all will be about 17-18 watts and all will put out the same amount of lumens.

Notice the 4200K color rating, well normally this would be a pretty decent looking white light, much truer or purer white than your average 2700K “warm white” CFL for your home. However this is a plant light so it doesn’t have hardly any green light in it and so it looks redish purple much like LED plant lights. This light would be fine for small vegetating plants, it still has quite a bit of blue in the mixture at 4200K on the rating where 2700 is red heavy normally used for flower and 6500K is slightly blue heavy and used during veg when using fluorescent lights.

that being said, this light is really only good for about a 1 foot by slightly longer than 2 feet area for veg, and it wouldn’t be a very aggressive vegetative growth, even with the brightest light you could get for the housing. Don’t worry about replacing the bulb right away, it already has about one of the best bulbs in it you could use.


#6

Thanks MacGyver, I really appreciate getting back to me. I took down my hps light and put up 2 of these lights for now thinking that it would be better than the hps during the veg stage. I only have one that’s about a week away from switching to flowering. Two more are about a week old as I killed the previous two. At that point I will hang the 2 hps lights I have back up, (I have 2 now 150 watts apiece) and will figure out what to do with the babies then. I also found on amazon the perfect light for the veg stage and will be getting 2 of those next week. Their T5 grow light (2 ft 4bulb) that toucan daisy chain together. Would you recommend this? I’ve done to many things without researching them or seeking some guidance, so I can’t express how much your feedback means. My wife doesn’t know, doesn’t care. One more question though. One of my new seedlings came up with just one leaf on it. As I stated earlier it’s about a week old and although it’s growing it doesn’t look like it’s anything else. Should I pull it and start over or keep going? I’m going to let these grow out and then replant 4 in my space to keep everything together. It’s a small space, 2.5x2.5x5ft. That’s why I didn’t think I would need much in the way of lights. Way wrong there. My strains are w/w and og. Thanks again for the help.


#7

T5 fluorescent lights are totally different than t8 lights. A t5 with 4 bulbs could potentially be a very good light for your dimensions for the entire grow. I’m not sure of the discussion you had with Latewood or what you guys had in mind so I can’t comment further on that.

I think you need to do some research and get a better understanding about lumens, LUX, or FLUX/PAR. here is a loose guide on lumens so you can have a general idea of what you need or what you might want to do. You might still have the best lights for veg or bloom with the 2 HPS. Vegging does not really need a different light, it is just vegging can be done with less light than bloom, blooming/fruiting needs the most intense light but veg can have intense light as well for better faster vegging growth.

Lumens(or equivalent PAR) per square foot:

No matter the type of light, if you can find the exact specs for its lumens/FLUX per square foot (or the equivalent PAR for red/blue only LEDs) you can use this as a loose guide as to what you need as minimums:

Seedlings and clones require about 400-1000 lumens per square foot.

Vegetative growth requires about a minimum of 2,000 to 3,000 lumens per square foot.

Flowering requires about 5,000 to 10,000 lumens per square foot, ideally, and can take possibly much more.

10,000 lumens is supposed to be about the average power of the sun at sea level on a clear day at high noon, or something like that, lol. 8,000 - 12,000 lumens is supposed to be about the average power of the full sun without any overcast or no clouds depending on altitude and potentially other factors.

It’s not ideal, but you can make do with 2,000 lumens for an entire grow if necessary.


#8

Thanks Again for the feed back MacGyver. Yeah the light I have on the way is 10,000 lumens and a light temp of 6500k, the 2ft 4 bulb one. I was thinking that when it comes time to switch over to flowering that I would keep that along with the hps light for the max light possible. I’ve read one site saying, very adamantly, not to use hps lights during veg as this will cause the plant to stretch too much. Another says just the opposite and also that it’s one of the best lights to use. I realize that experience will be the best teacher but I’m just trying for a leg up here and get the best yield I can first time out. Also the the hps is 16,000 lumens but it doesn’t say the light temp. It states that it’s a full color spectrum. I’ve read and read and read till my eyes hurt and I’ll read some more. So thanks again for the help. Take care.


#9

Yes, excessive stretch usually is more because of not intense enough light. All lights that looks kinda white, even the “warm white”, pretty much have plenty blue light in them, you only need 20% blue light to keep a plant healthy and avoid stretch. When you have a full spectrum light, full spectrum usually means it has enough blue to avoid excessive stretch and enough red and blue to keep a plant healthy. Metal halide tends to be more balanced in that it has more blue light than a high pressure sodium light and looks more pure white or slightly blue white instead of the red or yellowish white light that HPS tends to look like, but it is not as intense or it does not produce as much overall lumens/FLUX as a HPS. Now you’ve heard it twice, for the most part HPS is the best light when it comes to lumens per watt, with the exception of a high quality LED. The problem with LEDs is that it is hard to know if it is really high quality without buying one of the extremely expensive name brand models.

P.S. Blocking one small segment of the red light spectra can reduce stretch even more but may not be healthy for the plant and is entirely experimental and as far as I know, no current light spectra actually use this technique. this is why blue-er lights are used for veg, as they will have less of this version of red, but if the light does not look totally blue, like a all blue LED, and it looks kinda white, then it has red and green light in it as well, equal parts of blue, green and red equals pure white light.