Ah true forgot I took into account effeciency for my original calculations.
Any thoughts on how the plants are looking?
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I’m not the best guy for diagnosing issues, but you could be onto something with underwatering. Sometimes they’ll turn away like that when the light is a little too intense as well. But you should probably wait on the others with a little more experience diagnosing issues by pic.
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@middlecoast didn’t you transplant out of those cups?
Yes, moved them into 5 gallon smartpots with FFOF. Haven’t put together a grown journal update yet.
tag me when you do the update. @middlecoast
Day 19 Update
After some help from @bob31 I went ahead and transplanted on Saturday. Wow was it needed. After some work I was able to remove the cup it was holding and here’s what I was presented with.
From here I dropped both of my plants into 5 gallon smart pots with FF Ocean Forest.
48 hours later… Here’s some top and bottom shots of the two girls.
I also decided to help with run off i’d place some gravel under the smart pots. I did a little test and was able to collect over a full liter of water before the plants touched the water.
Thanks again for all the help guys and for coming along for this lil journey.
The basics
Water/Nutes: Tap water, pH 6.5
Light: 250W at about 22" away from the top of the plants.
Temp/humidity: 72° F and 60% humidity at night; 78° F and 50% humidity in the day. Put humidifier on a timer so it won’t climb as at night.
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Nicely done! They are starting to look better already! Keep an eye of the color and see if they don’t darken up as well. They will love their new home as soon as they get situated. Might be a couple of days before you notice anything. @middlecoast
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I agree with Bob31 they look a lot better with roots getting air too!.best of luck fellow thumber
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Absolutely @middlecoast please do.
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Had a question for you all in regards to wattage and increasing it over time. I’ve read that its possible to actually give plants too much light. Using my build I can crank my lights up to 480W at the wall. I know there’s some efficiency lost in actual light getting to my plants, but its an easy metric I can measure and reference. So my question is, what wattage should I shoot for and when should I crank them to full strength?
Here’s my assumption… all guides say that you should shoot for 50W per sq ft, so with a 3x3 grow tent I should shoot to get up to 450W running. Now I don’t wanna crank up the light from 250W to 450W over night so I was thinking that it’d be smart to do a steady increase over time. Since i’m trying to increase 200W I was thinking of increasing things 20W a day over the course of 10 days. Is this too much for veg? Should I wait? I of course can just play with the power and see how things play out but rather learn from experience than experimenting.
Any thoughts @bob31, @dbrn32, @Countryboyjvd1971, @MAXHeadRoom, @HappyCamper ?
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I’m gonna defer to max and dbrn
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I think that up until the point you start actually light burning your plants, more light just means faster growth. So less light means slower growth. If you are not in a rush, you can keep it down to “full sun at the equator” levels. Much higher and you need to add CO2.
I know (from reading on this site) that a 600 watt HPS from 14" is full sun. LED is more efficient, but not by much. Beware of Chinese LED lamps that claim to be 1000W and only draw 350 watts from the wall.
And keep in mind that your LEDs are much more efficient if you run them cooler and with less drive current. So turning them down to half the maximum current does not equal half the light. It’s a lot better. Look at the datasheet for the LEDs. They have graphs and tables for light flux at different temperatures and drive currents.
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Another thing to consider is the distance between the LEDs (or lights in general) and the plants. You should be able to place your hand at the level of the canopy and it not be hot.
Ramping up the lights intensity or moving the light closer to the plants seems like a good plan. The plants will tell you when it’s too much.
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To be honest, 50 watts per square foot is probably going to be a bit much for you. But only because you’re running very intense and efficient light. The 30-50 watts per square foot is a great metric, unfortunately it’s based off hid lighting and sort of dated at that. Par levels would be a much better metric, unfortunately par meters are rather expensive. You do have a very popular cob though, I would think doing some Web searching would help. Or perhaps check for some manufacturer data for lights with similar design to yours. Timber probably a good start.
All things considered, the process you’re speaking of is usually referred to as light hardening. If you do this gradually like you’re saying, it will usually give you a little buffer zone. As opposed to just running them wide open, would surely create at least minor issues. The bigger part here, would be hitting the point of needing co2. Once you get over around 1000 ųmols, any more light would essentially be wasted without additional co2. Depending on your lamp height, your cobs are plenty capable of hitting that number in a 3x3. Because of the differences in every grow space, it may even take a few grows to find a good balance.
Here is what I would suggest… right now in the veg state, I would tinker with your heights and try to save the cash on power bill. The amount if light required to veg nicely is considerably less. But you’re going to want to leave any adjustments for probably 3-4 days before increasing intensity regardless of how you do it. Obviously, if you think you’re experiencing negative effects (bleaching or stretching) you should react to those immediately. Once you transition to flowering, then gradually start to increase your power. It will take some adjusting to get use too. You’ll be dealing with stretch, and eventually start to produce flowers. So it may take an adjustment of pot one day, and then adjusting lamp height for the next several days.
As long as you’re patient, and paying attention, it shouldn’t be too difficult to get the hang of. This is one of those cases where less is more. Giving up a few grams because you’re a little weak is way better than frying all of your tops.
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Sounds like a good plan. I have found when you get the lights to close the top leaves will start to turn vertical. You will need less light for veg, and full power for flower
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Thanks @dbrn32. I remember doing the math on my setup and figured i’d be around 900 ųmols and so would be in the 90% region of light efficiency with the only way to get better is to add CO2 like you mentioned (which I don’t want to do). I’ll do what you mentioned and play around with height and power for now to see how things go. I currently have it at 270W and its pushing 25K lx at the top of the plants.
What do you mean by this?
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Full sun at noon is about 100,000 lux or 1 kwatt per meter square. Cannabis can’t have evolved to take much more than this with our current level of CO2 in the atmosphere.
A reasonable approximation is to take a cheap light meter out at noon on a sunny day, lay a piece of white paper on the ground, and take a reading. Then repeat with the paper horizontal at the same height as your plants will be. Adjust your pot until you get the same reading. Your lights now supply “one sun”.
You could get more precise using red and blue filters.
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Thanks man. Makes perfect sense. My current lux at 270W is 25K.
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I don’t know that there is an accurate or linear conversion, but the one time I had a par meter and lux at the same time, 27,000 lux was equal to 350 ųmols. That was using Cree cxa 3070 at 24 inches. 300-400 is a pretty good spot to be right now. If you note the distance you measured at it could be a good reference later.
Figuring light distance and dimming levels is more of an art than a science. Every situation is going to be a little different.
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