Common Misconceptions

Ogracious

Well-Known Member
Let me start with a little introduction. I have been a farmer for a long time, as has my father and his father, etc. I do not have a whole lot of experience growing cannabis (indoors), but I have grown more food crops and outdoor cannabis than I can count without forgetting why I am counting. I have been perusing this board and others (RIU is by far my favorite) for a long time and I have noticed a few recurring statements that are a bit misleading. This can lead to incorrectly diagnosing plant problems and can point people in the wrong direction. I feel that knowledge is power and there is a lot of knowledge on this board. There is a whole lot to learn about growing cannabis and it can be overwhelming for a lot of folks. The less misinformation we have here, the less overwhelming it will be, the less frustrating it will be, and the faster people can figure out what is happening with their plants. Without further adieu, here is a list of common misconceptions that I repeatedly run into:

Common Misconceptions

  1. Drops of water will burn your leaves. It is possible for a drop of water to focus light and burn a leaf, but not when it is directly on it or when there is any movement. The drop would need to be suspended away from the leaf and be still to acquire such a burn. This is with the power of the sun, much more powerful than our 1000W HPS systems. If water drops could burn leaves, many crops would be devastated every year and it would likely cause many fires as well. A drop of water CAN "burn" a leaf if it is either too cold, too hot, or too rich in fertilizer.
  2. You can pH your water with lemon juice, vinegar, sodium bicarbonate, etc. Yes, this will change the reading on your pH meter, but it will slowly revert back to or close to your original pH. The reason this happens is because they are not buffer solutions. Simply put, a buffer solution has a weak base/acid and it's conjugate acid/base. These home remedies only contain either an acid or a base.
  3. You can't pH your water with lemon juice, vinegar, sodium bicarbonate, etc. Yes, I know I am contradicting myself, but it's a bit more complex than it seems. In a soil based medium, you can pH your water with home remedies for a quick fix until you can get to a hydro store. This is only the case if your soil is well-buffered, as the pH revert back if it's not. Do this too often and you can destroy your soils pH buffering capabilities. I would not recommend you use these with hydroponic systems.
  4. Remove yellowing leaves. You should never remove a leave because it is yellowing! Your plant is doing this because either A) your plant needs something, or B) your plant needs something. In all cases, your plants leaf is yellowing because it is lacking something. Usually it is the lower, older leaves to yellow. This is typically because they do not get much light and it is more beneficial/efficient for your plant to "feed" on it. In other cases, you are low on a nutrient and your plant is getting it where it knows it can. Removing the yellowing leaf only perpetuates the issue and your plant will feed on another leaf. Let the leave naturally yellow and prune it when it is dead. Also, fix whatever nutrient problem you're having while your plants holds over with it's cannibalistic meal (unless you are in late flower, then leave it alone!)
  5. Green light is not used in photosynthesis. I've seen some very knowledgeable people recommend green lights in flower rooms to work or see during the dark periods. In actuality, over 50% of green light is absorbed by plants and is efficiently used in photosynthesis. Using a green light during the dark periods in a flower room will just lead to stress and possibly hermaphrodites.
  6. One light period is better than the other 100% of the time. For example, 24/0 vs 18/6. Yes plants will grow bushier and with tighter nodes in 24/0 lighting, but 18/6 does have it's saving grace! Dark periods do allow for accelerated root growth and can be helpful when needing to stimulate root growth such as newly transplanted cannabis or clones/seedlings. I recommend 20/4 lighting for this though as this allows the most efficient use of energy. Too much root growth (no such thing, really) can also lead to being pot-bound quicker, that is for you to decide if it is beneficial or not. I pot in oversized pots (in final transplant) to regulated temperature better, more stable environment, so additional root growth is always welcome to me.

Well, this is all I have right now, please feel free to add more below!

-Sap
 
Great information.....There's so much misinformation out there, it's nice to see someone post some realities.
 
You can pH your water with lemon juice, vinegar, sodium bicarbonate, etc. Yes, this will change the reading on your pH meter, but it will slowly revert back to or close to your original pH. The reason this happens is because they are not buffer solutions. Simply put, a buffer solution has a weak base/acid and it's conjugate acid/base. These home remedies only contain either an acid or a base.
doesnt that mean you could put vinegar in it, let it set for a day and then readjust, untill buffer (of the tap water) capacity is exhausted? Also another question. Why did i never had to adjust the water pH of any of my "normal" plants in the house, even the big ones and i have them for years, they r still doing fine. Tap water is pH 7,7
 
doesnt that mean you could put vinegar in it, let it set for a day and then readjust, untill buffer capacity is exhausted?

Somewhat. You can achieve your goal pH, but your pH will not be stable. Anything, such as aging nutrients, a dead bug, and many other things will be welcome to change the pH. Good question.

-Sap
 
Good stuff. I thought about the droplets of water in the sun "burning" leaves a while ago, i always finish off watering with a little sprinkle of whats left over the top of the plant, in the sun, never had an issue (light nute mix/neem dilutes) plants suck in the water through osmosis too so in any case the water doesnt stay there for long enough (evaporates too) to cause a problem
 
  1. You can pH your water with lemon juice, vinegar, sodium bicarbonate, etc. Yes, this will change the reading on your pH meter, but it will slowly revert back to or close to your original pH. The reason this happens is because they are not buffer solutions. Simply put, a buffer solution has a weak base/acid and it's conjugate acid/base. These home remedies only contain either an acid or a base.
Soma from Soma Seeds uses this exact phenomenon to his advantage. As he states, the pH of tap water in Amsterdam is around 8.5 He grows organically only. So what he does is use ascorbic acid to pH down to a low 6.2 for his watering, knowing that by the next water the soil pH would have drifted up to around 6.8-ish. His reasoning behind it is this: Different elements are each best and most easily absorbed at it's own unique pH level. So allowing his pH to drift up from 6.2 to around 6.7 as far as I recall, it allows for maximum absorption of each element while still staying within a safe pH range. I found it interesting. You can read more about how he grows on his website... I have never tried it, but I have huge respect for Soma.
 
  1. You can pH your water with lemon juice, vinegar, sodium bicarbonate, etc. Yes, this will change the reading on your pH meter, but it will slowly revert back to or close to your original pH. The reason this happens is because they are not buffer solutions. Simply put, a buffer solution has a weak base/acid and it's conjugate acid/base. These home remedies only contain either an acid or a base.
Soma from Soma Seeds uses this exact phenomenon to his advantage. As he states, the pH of tap water in Amsterdam is around 8.5 He grows organically only. So what he does is use ascorbic acid to pH down to a low 6.2 for his watering, knowing that by the next water the soil pH would have drifted up to around 6.8-ish. His reasoning behind it is this: Different elements are each best and most easily absorbed at it's own unique pH level. So allowing his pH to drift up from 6.2 to around 6.7 as far as I recall, it allows for maximum absorption of each element while still staying within a safe pH range. I found it interesting. You can read more about how he grows on his website... I have never tried it, but I have huge respect for Soma.

Thanks for the comment! That sounds like a good read, I will definitely look into that. The theory sounds good, I would like to see how it does under lab conditions.

-Sap
 
  1. You can pH your water with lemon juice, vinegar, sodium bicarbonate, etc. Yes, this will change the reading on your pH meter, but it will slowly revert back to or close to your original pH. The reason this happens is because they are not buffer solutions. Simply put, a buffer solution has a weak base/acid and it's conjugate acid/base. These home remedies only contain either an acid or a base.
Soma from Soma Seeds uses this exact phenomenon to his advantage. As he states, the pH of tap water in Amsterdam is around 8.5 He grows organically only. So what he does is use ascorbic acid to pH down to a low 6.2 for his watering, knowing that by the next water the soil pH would have drifted up to around 6.8-ish. His reasoning behind it is this: Different elements are each best and most easily absorbed at it's own unique pH level. So allowing his pH to drift up from 6.2 to around 6.7 as far as I recall, it allows for maximum absorption of each element while still staying within a safe pH range. I found it interesting. You can read more about how he grows on his website... I have never tried it, but I have huge respect for Soma.

This is exactly what I do. I do PH my teas to 6 and it always drifts up to almost 7. Dolomite lime seems to make this very easy.
 

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  1. You can pH your water with lemon juice, vinegar, sodium bicarbonate, etc. Yes, this will change the reading on your pH meter, but it will slowly revert back to or close to your original pH. The reason this happens is because they are not buffer solutions. Simply put, a buffer solution has a weak base/acid and it's conjugate acid/base. These home remedies only contain either an acid or a base.
  2. You can't pH your water with lemon juice, vinegar, sodium bicarbonate, etc. Yes, I know I am contradicting myself, but it's a bit more complex than it seems. In a soil based medium, you can pH your water with home remedies for a quick fix until you can get to a hydro store. This is only the case if your soil is well-buffered, as the pH revert back if it's not. Do this too often and you can destroy your soils pH buffering capabilities. I would not recommend you use these with hydroponic systems
Could we plz get to the bottom of this if stuff like Lemon Juice or vinegar works or not. Im Kind of understanding what you r saying there and Kind of not.
What I think: step one lower pH with vinegar, wait a day then readjust. This will destroy the buffer capabilities of the tap water.
So now you have ur pH 6,5 water and put it in your around 6,5 acidic soil. Why would this "destroy the buffer" of my soil???

Because like 90% pH minus producs i see usually just have some acid in it, no mentioning of any buffer...
 
Could we plz get to the bottom of this if stuff like Lemon Juice or vinegar works or not. Im Kind of understanding what you r saying there and Kind of not.
What I think: step one lower pH with vinegar, wait a day then readjust. This will destroy the buffer capabilities of the tap water.
So now you have ur pH 6,5 water and put it in your around 6,5 acidic soil. Why would this "destroy the buffer" of my soil???

Because like 90% pH minus producs i see usually just have some acid in it, no mentioning of any buffer...

There is a specific amount of weak acid/base that a buffer can absorb before it reaches it's capacity and "destroys the buffer" as you put it. What I was saying is that if you grow in soil, you can use those remedies in a pinch, but if you do it too long you will ruin your soils buffer capacity. Apparently some people use this to their advantage (see above).

All pH up/down products are buffered.

Hope I don't sound short, eating dinner simultaneously...
 
but r u sure it will use up the soils buffer capacity if its "fed" with something of the same ph/ph range, because i think the buffer would not to have to "Balance something out"
 
There is a specific amount of weak acid/base that a buffer can absorb before it reaches it's capacity and "destroys the buffer" as you put it. What I was saying is that if you grow in soil, you can use those remedies in a pinch, but if you do it too long you will ruin your soils buffer capacity. Apparently some people use this to their advantage (see above).

All pH up/down products are buffered.

Hope I don't sound short, eating dinner simultaneously...

Adequate amounts of Agricultural lime and Gypsum OR Dolomite lime should make it a non-issue really. It will take a LONG time to use up the buffering capacity of the soil. Living Organic Soil growers use acidic compost teas all the time. A good soil mix = no problems.
 
Adequate amounts of Agricultural lime and Gypsum OR Dolomite lime should make it a non-issue really. It will take a LONG time to use up the buffering capacity of the soil. Living Organic Soil growers use acidic compost teas all the time. A good soil mix = no problems.

This is absolutely true. When adding additional buffers [such as lime] to soil, you will not have any issue in this lifetime. I am sorry for coming off differently. I mix AgLime into any new soil for my cash crops on my property and I should not have to add any more until it is my sons farm. I personally do not mix it into my soil for cannabis, but there of course are many that do.

Edit: I did want to note to people with the horrible idea of adjusting the pH of their compost tea. DO NOT DO IT. Let the amended soil adjust the pH naturally. You do not want to shock/kill bacteria that is present with sudden pH swings.

-Sap
 
Commo. Misconception- more is better

This is very true in a lot if cases! Especially in the case of "more plants equals higher yield". There is only so much X amount of light can produce. Though, one should always feel free to stretch the limits of their setup. I just watched a video where a guy grew two Super Lemon Haze under a 600w and a Trainwreck under a seperate 600w and they both yielded 14 oz each, which yielded more than his previous grow of more plants as well.

Here is the video if anyone is interested...
m[video=youtube_share;PkZud2Yk1Ok]http://youtu.be/PkZud2Yk1Ok[/video]
 
Another common misconception: You must do what everyone else is doing to succeed! Absolutely false! If it wasn't for people trying out new ideas, marijuana cultivation wouldn't be where it is today. Be that person that pioneers a new method. Sometimes, just because it didn't work for someone else doesn't mean it won't work for you.
 
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