I agree with with Budsy, its like reading my own grow log. I seem to be getting more Mag and P deficiency as well as the droopy leaves. I have been raising my lights this week and I have seen the leaves start to raise up as I raise the light, I am at 24 inches atm and that seems to be making them a lot happier.
Its hard not to fall back into the lower heights when you have been growing like that for a long time. Also I see other people with no issues growing 3-4 inches above canopy with higher wattageās with the Gen 2 strips on other sites which just confuses the hell out of me.
For me, I notice the plants can take a lot more light once they get bigger. As the plant stretches in flower, it can get a lot closer to the light too.
With HPS, we often run into heat issues before we have too much light. With the LED strips, there is very little heat.
One last thing to remember is light may not be the limiting factor. If the environment, nutrients, or CO2 are not adequate, more light will not make more yield.
well consider typical indoors environments will have a raised co2 level from atmospheric and are typically double to upwards of triple the levels in newer more efficient homes.
also like @ReikoX said and i mentioned a couple posts back on the whole liebigās law of minimums, is i may be running into other limiting factors first and the light intensity is just pushing it past a detrimental point. Like i know im not forcing run off like i use to in the past in a way to avoid saturated pots and a few other issues, but that could be the difference.
and yeah you would assume flowering plants would see less issues as there more apt to take the higher levels of light vs growing young plants, something else to consider though is say lights are hanged at the same height with a 18/6 cycle but run at 2/3rds the power of what you would run them at with a flowering cycle of 12/12 from a day perspective they would be receiving the same amount of light in it.
Guess for myself i need to start working back into forced water cycle overs a bit more and see if the plants can handle it with the higher light levels.
@Shadey, is it just plain wine? Did you add any yeasts or sugars to it? Also, how much ppm does that raise CO2? Iām very interested in this low-tech idea for generating CO2.
Any pics?
Hi firehead, its a wine kit for making wine, I dont know how many ppms it produces, but probably 5 times what is needed, just breathing in the same room will increase ppms above 750.If you just wanted to make CO2 using this method then a 5 gal bucket with 10 lbs of sugar and some brewing yeast would do. You need an airlock and a saleable lid. you can control the amount of CO2 being produced with temperature. 68F up to 78f is the range yeast likes. If you run your temps at 75F the 10lbs of sugar will last about 8 -10 days for the yeast to finish.
When I run my flower room in the summer, I have it as a semi sealed room with air conditioning, and a little tiki torch made out of half liter mason jar, and run for about 6 hours a day. Labrat uses the same technology and he has a CO2 ppm meter and says its above 1800 all the time its burning. The wick is only a 1/4 inch and the flame gets no higher than a half inch, you could do the same with a tea light candle. The important bit is remembering to put it out before the lights go off
Edit The only bugs it attracts are fruit flies which do no harm to the plants.
@Mr.Sparkle : Have you considered testing DTW, compared to your current re-circulating setup? I wonder if having fresh nutes every fertigation would make a difference (to the problems youāve noticed with increased light levels)? Iām currently designing a new micro grow and weighting up DTW vs recirc in coco.
So something ive been following today reading wise and would be differences in between my own past result and current is grow temps, but a stipulation here for a more accurate metric is leaf temp.
So a example of the discrepancy is say you take the old recommend āroomā temps of 78-82F using yankee measurements for say what was ideal temps under HPS, well HPS puts out alot of extra IR heat that gets absorbed by the plants so much so that even though room temps may been in those ranges your leaf temp in actually more in the high 80ās to low and mid 90ās or more even if the air isnāt. Now in comparison typically with more modern leds our leaf temps are a few degrees cooler than ambient as they arenāt producing that excess IR heat but when you compare say you had two rooms same light levels same air temps but plants under an HPS had leaf temps of say 93 degrees, and those under LED had leaf temps of 73 degrees, thats a huge friggen difference as far as transpiration and growth differences are concerned.
So guess thats one question for both you @BudSy and @Shadey what have your room temps been at but more specifically what are your leaf temps if say you have an IR thermometer on hand.
Cause to me with my more adequate and even air handling of current, having the plants run at a cooler than ideal leaf temp could be that factor, as the temps donāt warrant the transpiration possible to keep leaves cool at say higher light levels, but are instead limited by it.
DTW or recirculating depends on the refinement but consider my setup is dtw to an extent it just happens over the span of a res fill, as if i am forcing run off, that builds up into whats left in the res on change over, and if off on my feed amount and or not forcing enough to cycle over that does build up in the mediaā¦
DTW though you can force a specific setpoint vs re-circulation like my application where it slowly raises over the length that a res fill gets consumed
but no i havenāt specifically tried that variable as in feeding fresh nutes every watering, but i also havenāt been forcing any runoff so my reservoirs stay pretty consistent from fill levels, which not having much runoff could be that other factor too
Hmmmā¦ can I ask how often you refill your res? Iām building a single plant 5sq/ft flower chamber thatās very height restricted, currently trying to decide how to manage runoff vs recirc - runoff would steal less of my vertical height.
may i ask whats your overall height ? and definitely dtw is easier to go in height regards as you can have a side reservoir and just a collection tray.
As for my reservoirs it depends on how much i fill them and how much im watering, normally i only fill about 3.5liters or so each but that can last 4-7 days, if they are filled more and depending on plant uptake and how much im watering it can be stretched to 10+days, but doing changeovers once a week is nice to do.
Itās a 28" cabā¦ Iāll be using the Bridgelux Gen 2 lights mounted to the roof of the cabā¦ obviously reading through your thread is giving me lots to think about (thanks for that).
Yeah 28" isnāt much for a one plant 5sqft grow, my cabs are at 28.75" floor to roof but yeah just a bit easier to manage a few smaller plants than one, still doable though forsure.
Oh and consider I have 4 resās in my two cabs which is 6sqft total so just figure that in to those amounts I fill them up with
I have always found this area a little confusing but what you said makes a lot of sense. My grows during this time were definitely far from optimized. I had not grown for about 20 years then spent about 20 thou in about 1 month on equipment and built a room so you can imagine how much dialing in was and still is required. Guess what was part of all that cash. A big fat air conditioner so I could easily keep temps under control. So i definitely could be falling into this scenario. So in effect, raising the room temps (or lowering the humidity?) could lower the stress on the plant by allowing it to transpire more and fueling the processes allowing it to process the light? Am I getting that right? So It just so happens I purchased this about 3 weeks ago but I doubt it would be accurate enough for what we need. Its a 20 buck special:
EDIT: Oh hang on, i just realised you mentioned the difference in leaf temp was about 20 F (about 10C off the top of my head) so perhaps this IR thermometer will be accurate enough to give us some idea. Watch this space.
Ok, so I am not overdriving the plants right now with light and they are in their last week of flower so the tents temps are at 25C/77F. I have 560Watts coming from new LEDs in a 4x4. So the tent is running cooler than usual but the leaf temps are only 24C/75F and the lights are only 12 inches from the plants.
that thermometer should be plenty accurate enough its similar to what i use but mines 15-20 years old and not a gun style one, just consider IR thermometers donāt do well will reflective things the factor at work is called emissivity, Emissivity - Wikipedia but a chunk of tape on say a tent wall is all you need.
But back to leaf temps, there is some literature and videos out there that say ideal leaf temps are around 28-30C, for us using ledās that donāt heat up the plants say compared to how HPS would that might mean we have to run at higher temps than you would think is optimal due to past knowledge of temps growing under different light sources, needless to say its something else to play with to see how much of an effect it may have.
well statistically the lower the wattage or light per area will favor higher yields given that amount of light vs a higher one to a point, what i mean by that is it doesnāt scale linearly and that lower powered grows may get you those higher gpw numbers though the yield isnāt as nice, like you you rather have a 1.5gpw at that 100w level or 1.35gpw at that 150w level, also id say just go for the 150w build unless wanting to play with that efficiency metric for fun.
I just measured my leaf temps 74f in the clone cab which is running at 78f and 69-72f in the veg tent which is running at 75f soil temp in there is 68f, so the bacteria will be running slow as well. I will stick the driver in the veg tent now to keep the heat up higher and see what happens.
