A very sad tale

I think LEDs deliver.. i dunno x5 the intensity per watt to the plants. Maybe even more... x8? I read that HPS is already massively inefficient and all that heat is literally energy thats not being turned into light. Then you have to factor in that HPS bulb shines 120 degress downwards, all the rest of the light goes up into the reflector. I dont know the maths but reflected light is significantly diminished isnt it? So the bulb only puts 1/3 of its output directly down compared to LEDs that fire all of it downwards at 120 degrees. I suspect that this is where some of the problems come from.

Im also finding that the light intensity figures you get from the internet just seem to be all wrong, particulalry for small plants and seedlings. For me the LED seem to work well once the plant is past a certain point, im even starting to get some growth speed back, but getting past the early stages without distress are proving damn near impossible for me so far. I find myself again on the path of lowering the light intensity. Round and round in circles.

I have definitly got better plants from growing dry tho, im just having problems putting food in and have started to experiment with higher doses of nutrients. I have also started my own new way of giving water. I poke my finger to make a hole in each corner of the pot and water down that hole specifically and nowhere else. This is allows the plant to keep at least half its roots mostly dry and i have had good results like this.

This is all really werid and unintuitive. It flys directly against the estabished knowlage of wetting all the soil. I still beleive i can make LEDs work.
 
dankd said:
https://www.icmag.com/threads/led-feed-demands.366485/
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Thats a good thread. The purpling that i suffer from can be seen at the top of page 11, the weird darkening that looks like too much N, and also slightly further down in the beer cups. Also i spotted some of the twisting in that thread aswell. Exactly my symptoms.

The reason i doubt the temperature theory is that i get a couple degrees above outside temps, so in the summer its 28 dgrees +. I cant swear to it but im sure i saw 30c with the lights on in summer, so im not ready to accept that yet. Leaf temps might be a different thing.
 
someone said the leaf temperature is higher with hid than led because of the radiative heat so the metabolism is sped up but with led there is much less radiative heat so the plants will struggle because the light demands (of very bright full spectrum leds) outpace the metabolism rates

i would not flower cannabis indoors at anything over 27°C that's where the potency starts to drop fast. although i don't know how that translates to high temp led growing
 
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I've read that the radiant heat provided by HID stimulates the opening of the stomata's on the leaves thus making photosynthesis possible and stimulating it.

Problem with LED's is that they don't do this in the same way. Radiant heat is far less however the light intensitiy (energy of photons) can be many times stronger.
This disrupts the proces of photosynthesis and creates inbalance in food uptake, H2O uptake and CO2 uptake.
The bigger amounts of energy tell the plant to kick in higher gear but they are in way also more restricted.

I guess you can see it almost like having a big block supercharged engine running on ethanol but with restricted air intake and exhaust system.
It aint gonna fly!

That's my take on it anyway.

25-26°C with a nice breeze and enough air exchange worked good for me in the past. Make sure that you keep your humidity in check (high enoughà and don't create an environment that resembles the dessert.
Like @musashi said before, Silicium and Cal/mag promote and aid the proces of photosynthesis.
 
dankd said:
i still remember a townhouse basement in '94 and a 1000w mh on the ceiling and planting thai seeds on the concrete and before they were 1/2 foot tall they had fan leaves the size of dinner plates haha

btw 150w mh bulbs are super rare i hope to find one that i can use with this light
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I once scavengered some from streetlights when they switched to LED. Still got a few aluminum streetlight reflectors...never used them...but thats really the only time i came across 150w bulbs...
 
Proud Kraut said:
I once scavengered some from streetlights when they switched to LED. Still got a few aluminum streetlight reflectors...never used them...but thats really the only time i came across 150w bulbs...
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for some reason i saw 100/150/175 w mh available at grow shops in the usa but not in canada. hydrofarm makes my hps named mini sunburst and the bulbs are agrosun and there is a 100w mh version but only sold in the us

i will contact hydrofarm for replacement bulbs and ask about getting an mh i hope the ballast is compatible
 
btw i switched back to led, but only because they make the hps grown plants photograph so pretty (inlet ceiling leds in the apartment)

i don't believe now that keeping the led would have gotten me this quickly back on track with perfect healthy plants like this. like buy the soil and the light at crappy tire, cut the bag in half, pop 4 legal seeds in and add water : )

not a hint of anything on the edges, colouring is perfect, sheen and suppleness check, very fast growth. complete improvement

456.jpg
 
dankd said:
here is an interesting discussion about led and hid at 1:05:57

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Aside from the nostalgia i think bottom line was a (quality) LED outperforms the bulbs. The part about different cultivars not performing comes probably from genetic preferences and not dialing in in these fast production cycles.
The Mango Kush x Bubblegum Chemdog they showed in the 2/3rd HPS 1/3rd Plasma room for example didnt like much N and was giving denser flower in the mid and lower sections just gave that expression of a classical Haze/Diesel feed preference plus a foxtail issue that can come from heat or just another part of the story where certain cultivars finish better on diffuse light. IMHO in this case it could alse very well be that the DLI needs for this plant are way lower than the one right next to it. So the lowers getting less DLI because of shading finish bettee because theyre happier. Just a theory.
 
added two of the four bars of led at 15% to the hps (150w) and then after dropping it down to just one bar at 0% the plants finally went 'boyoyoyoyoing'. makes sense because any more led than that and the hps is out shined already. must have found the sweet spot : )

here is the lone keeper afghani still not showing hairs or sacks at almost 2 months with a bunch of new promix veg and herb mix soil and a shit load of promix 4-4-8 granules (both omri). i made the mistake before at canadian tire of buying the soil they brought from the back, last one, dry and banged up, shipping stickers and dust all over it. this time i got from a new skid and the bags were super moist and heavy

also a ladybug

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put a few inches of sand down and the fungus gnats are gone, and it seems the plant has responded well also. i am guessing that it is keeping the surface area of the soil moisture sealed and now the roots can grow all the way to the edges of the bin. wow

also just realized i should have made a sexing box much sooner as the plant has still not totally revealed itself. this clone is under 10 hours light so should be just a few days to find out. could have done this over a month ago d'oh

one thing about the hps grown plants is the inverse leaf colour scheme thing is not happening like with the led. in this pic the leaf panels are the darkest and the veins are lighter across the entire plant, and, the stems are not red or darkened at all. whereas the led grown plants often tended to show the opposite, with the leaf panels being the lightest and the veins the darkest. these two differences are tell tale led grown when i see plant pics now

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Well.... :)

After experimenting and experimenting a picture starts to emerge where if you divide the stated numbers by 10 everything works ok. Like, small plants veg perfectly well under 35-40 µmol. Iv never seen a plant that was happy under more than about 80+ µmol in veg at least. I know they will tolerate alot more in flower but tolerate is not the same as thrive. Seeds started under 50 µmol will suffer distress, im going to try for 20-25 cause getting much lower is difficult in itself, but it turned out i was on the right track all along. Once i got my watering sorted it was easier to understand but i didnt want to accept what i already knew because it throws up a few different possibilitys. First possibilty that my set up is an anomoly, not likely. Second possibility that my spot on par meter is reading wrong, it reads sunlight at pretty much the stated numbers you can find online. Is it the way the meter reads thats thrown me off? Could be.... Or the last possibility is that the entire thing is a conspiricy to make people over spend on lights. When i bought my light i got it at quite a bargin price and i got the distinct impression the seller was glad to get rid of it. When i asked the seller a question about intensity i got a strangely evasive reply, which seemed odd at the time but i let it go. Almost as i if he knew it was massively over powered. This is if you could dismantle the bars i feel like you could light 4 or 5 square meters at 50% Strange tho cause it looks much less bright than my old bulbs. Those old bulbs must have been massivly wasteful and even worse in a cool tube.

So yeah... hmmm. I welcome any opinions on this, whats going on? :) Doing ok with 2 bars at 25% but i would much rather be using 4 at 10%, anybody know where i can get an off the shelf dimmer swith to replace the 5 position dimmer that comes with it? Or at least the parts to make one myself?

My plants are still very hydro phobic but will accept a little more water. Im starting to feel like soil moisture and light intensity are on opposit ends of a scale, up to a point. BTW i limed my old soil back when i started this thread. I think its alot better than the bio terra plus i use as a benchmark to compare to. I only use blood fish bone these days but do add boost, zym, rhizo and superthrive in various amounts. Micro doses rather than bottle doses.

Im saying allthis assuming im going to get a proper crop this time, but i got normal looking branches for the first time in a while so i think its all going to be ok :)


dankd said:
put a few inches of sand down.....
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Just from looking at your top picture, those plants have early waring signs all over them. If they were mine i would lower the intensity even further. See that growing top at bottom center, see how the very tips of the leaf are dark, see that kind of cow horns shape the fingers make, how the creases in the leaf are deep, i read that as light stress and it does seem to creep up. Even after the intensity is lowered the symptoms will continue for a while.
 
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it's the training that made that shoots' leaves incongruent. although there are some remnants in the damaged older fan leaves at the bottom of the plant, from the near fatal feed shortage which i corrected by using fresh soil and heaps of fertilizer. i dialed the light down from 150w hps + 2 bars led at 15%, and finally to just the hps and 1 bar at 0% and it was at that point that the struggling plant went 'bing' and began the recovery. as far as i can tell this is the sweet spot as far as light goes for this space

i should say though that that plant was male but i did take a clone and have started 4 ortegas. i also was just pleasantly reminded of how last year i looked at tetsuo's ortega grow and how i would never be able to get plants nearly as nice looking, with such a lush dark sheen on the leaves and incredibly healthy until harvest time

now i know i can because i too am using hid (with a lil led)(!)

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