Will 150w HPS outperform 372w of T5HO?

Here's an interesting mystery...The T5HO girls are showing a lot of clorosis. The HPS light Girls are not. Same water and nute schedule, same lighting, only difference is type of Lighting....Any guesses why? I sure don't know.
They started 12/12 one day apart....Sorry about pic #3. :stoned: I had to tilt my head to look at it!

Side by side...

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and the rest...

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Plumper plants, denser buds require more nutes. But if you're within 2 wks of harvest, you don't want to feed or you'll taste it in your buds. Check your trichs closely. If you think you have 3 or more wks to go, give a feeding. The most yellow leaves will fall anyway. This happens because the buds are pulling energy from the leaves. Its time for molasses if you haven't already. If the sunleaves fall at this point, its not a big geal. Remember, the calyx goes through photosynthesis like a leaf, hence the green from the chlorophyll. I think I'd go ahead & give a bloom feeding & a shot of molasses. The pics are too sm on this cell phone for me to be able to see the trichromes, but I think your far enough from harvest to give at least 2 more feedings. Basically, they are just farther ahead of the hps because of more lumens, so just remember, more light, more plant bulk, means there's more need for nutes. Do you have anything to view your trichs with? Its time to start watching. :) :) :)

Thanks Catbuds, they are 4 weeks and 2 days into 12/12 so I have time yet. They first plants did the same thing so I wasn't too worried about it. I left the fans alone this time though. I was cutting them off the first time around...:(
I have given them Canna Flora 2-2-4 with molasses mixed in. The Canna since they went to flower and the molasses started about a week ago.
Just odd how it's only the 2 plants under the T5's, not the two under the HPS...Spectrum? Heat? The 4 foot 6 bulb has 2, 6500k and 4, 2700k bulbs with 24' 6500k sidelight.
150 Watt HPS with a couple 26W? CFL's....No Clorosis.

Its really not odd at all. The fact that there's more bulk to both the plants & buds just means they require more nutes than the hps plants. Compare it to a pregnant woman. Her body is programmed to first supply the baby with nutrition. The buds are the plants babies. Do you have any veg nutes left? If you do, add just a couple of drops (I do mean just a couple) to your bloom nutes & molasses the next time you water. But, new daddy, don't fret too much if you loose the yellowed sunleaves! The calyx & bud leaf will photosynthize & produce energy for the buds. & DO start keeping an eye on trichromes. Dont be surprised if the T5's ripen before the hps. BTW, HAPPY NEW YEAR!!!! ;) ;) ;) ;) ;)

There's no clorosis with the hps yet because they aren't using the nutes up as fast since they aren't as dense or developed as the T5's.

Just like catbuds said...twice. If you had a plant in the corner with less light it may very well never see senescense (leaves changing color fro old age). I've had some grows throw it's fan leaves starting off early in bloom cycle and other grows where they never did loose it's fan leaves. Loosing the leaves later in bloom is not a bad thing. If your plant is loosing lots of leaves early on it's probably hungry.

Happy New year to all!! Now pass that thing.

Thanks all. Really though, what had me wondering was the fact the Clorosis was well started earlier in development than the HPS plants are at now.
In other words, I had visible Clorosis in the T5 plants prior to the development stage the HPS plants are at right now....with no sign of any developing Clorosis.
You will have to forgive me....I tend to get hung up on "why's" sometimes. I'm not trying to beat it to death, I just want to understand it.
In my mind, if the HPS plants end up never exhibiting that kind of Clorosis it tends to point towards an effect of the lighting. Since the HPS light (and the 2 CFL sidelights) are in the 5K and above spectrum, it leads me to believe, (at this point anyway) that there is a correlation there.
...or maybe I should just STFU and figure it out. Then I will know. ;)

Well, I do know that red light tends to be "better" for flowering. But the reasons behind this still puzzle me. It is true that Cannabis uses red light to time itself, but I don't understand what the connection to chlorosis might be. One thing to consider with all of this, is that often it isn't enough to just know wattages, lumens, etc. What's really critical is PAR (Photosynthetically Active Region). I use a PAR meter in the lab, but haven't used it yet for my home grow. PAR measures the intensity of light in the relevant wavelengths, and ignores others ( for example, green). It is often surprising to discover that what appears to be a very bright light source may have fairly low PAR levels. This is the measurement that would be really useful in comparing your setups. Also temperature of the soil/water can affect nutrient absorption. Colder temps tend to inhibit uptake of minerals, especially phosphorus. You might want to stick a thermometer down in the pots and see if there's a difference. OR, we could both just STFU and let the plants do there thing.:D

Just my :twocents: but thinking maybe we should think in terms of the seasonal patterns where the strain your working with are like.
Like: Fall light because of the angle it hits atmosphere, changes it color a little. Mid-summer(veg) more straight in, more uv and blue.
Time length varies of course, as does temp, and maybe moisture. I think we can optimize everything but if we get to far off base, mother nature will pick us off.

Of course maybe I'm all wet, and global warming and the hole in the ozone layer are good things.

Hi guys! Catbuds pointed me over to this thread and I'm glad I'm reading it. Some really nice info, Chromophore and OMB. And makes me glad I chose T5 HO's when I started to grow last year. Plants have done really well under them and I think they're the way to go for me. I'm all for learning more about lighting and feeding our little friends. (Little - well I have some large plants this time 'round, so maybe I shouldn't say little....)

Peace and Happy New Year.