Disasters

[Unit]

ot - I'm quite surprised you don't have a CO2 source in your room - is that because of the ventilation system?

I've read on this site that you can mix a quick and easy co2-giving solution out of water, yeast and sugar. Your thoughts on this?

Unit

[oldtimer1]

DeLata I only had one spare otherwise I would have replaced all 6.

Unit I try and grow organically, so don’t use fertilisers at levels that force plant growth, cannabis is naturally adapted to growing in air with 350ppm Co2 levels. I can give them that by changing the air they are in quickly enough to maintain Co2 to normal fresh air levels.

I have played with Co2 systems! With any of them to work ventilation has to be off and circulation on while Co2 is being added. Temperature controlled air conditioning is essential to make it work really well not just the temperature but also for humidity control, in other words complete control of the environment.

If you want my opinion fermentation is a waste of time, as its uncontrollable, you get approximately 500 grams of Co2 for every kilo of sugar fermented right out. It is produced 24 hrs a day, during the dark period it will hinder the plants so it needs to be completely vented out side of the grow area. During the light period it either needs to be released above the plant tops or driven in with the air circulation fan. Ventilation [input/extraction] would need to be cycled for it to work, something like 17 mins off 3 mins on. So aircon would be needed. You need 20+ gallons of must, renewed every 2 to 3 weeks to bring Co2 levels up to 1500 to 2000ppm in a small room, maybe several fermentation tanks with overlapping fermentation starts as peak out put of gas is only over a few days. Its a nice idea but not very practical. To really verify the day to day levels, a Co2 reader would be needed, as going much above 3000ppm can kill both plants and humans. Not a problem in normally ventilated rooms but it could be in a sealed grow area with the ventilation off. Personally I think the best results are between 1300 and 1500ppm I would set the reader to trigger an alarm if the levels ever topped 1800ppm.

At the end of the day its much cheaper to have an effective system that does the job properly. For this a Co2 reader and control box, controlling the ventilation, compressed Co2 release valve, lighting and cooling. This providing you have already sorted your growing to peak output can double your yields! But my prob is it changes the bud form, the taste because it needs more ferts to accommodate the additional growth there is also more leaf and chlorophyll. I just don’t like the taste of the end product. Even with computerised control it is hard to get it right, interestingly in Holland most of the big growers have dumped Co2 in place of fast ventilation, the result is yes slightly lower yields but less losses from fungal probs so at the end of the day they have more salable end product.

The practise of commercial growers adding both systemic fungicides and insecticides to the reservoir to try and keep their plants healthy because of the softer growth under enhanced Co2 is a practise I condemn utterly.

[oldtimer1]

M.A.T systemic insecticides are what they say, they are in every cell ot the plant. Mostly nerve poison types, an insect or mite bites the plant and it kills it. Systemic fungicides also reside in every cell making the plant toxic to any fungus that tries to invade the plant. Some of the chemical used by these guys are not even cleared for food crops let alone something that is going to be smoked. Do I want to risk smoking something like this? Should any one else? I don’t think so!

[Arnold Layne]

Just to underline that OT1, I saw some commercial Skunk recently - huge buds, I mean massive!; High, moderate; smell and taste - Aweful! like smoking a chemistry set; side-effects, headache, dizziness.

I did not purchase it, but opted for the rather nice Thai instead!

Worrying to think this stuff is being produced. The quantity I examined {around a half kilo} showed that advanced pressijg techniques were being used, and the bricks were already showing signs of mould since the pressing and sealing in cling film must have taken place long before the buds were dry.

[Labrat]

bump!

just because that is the most comprehensive and clearly explained answer to a question thats been bothering me most of today, (whether or not to add a CO2 controller).

Thanks OT1, you've just saved me making a very expensive mistake.

[stonpony]

LaBrat;

Perhaps I am mistaken, but I think you may have misunderstood OT1...It is the systemic insecticides/pesticides that he opposes, not Co2. Co2, is an incredable addition to most gardens, and as he posted if the Co2 had not run out damage would have been minimal.......don't give up on Co2 just yet......stp

[timbuck3]

cheers oldtimer1

there should be like a school in holland where you can learn how to grow.....seriously....could make good cash.....

[Mr. Jolly]

That was a good call dr rockster bumping this one up, as I think it may help me to diagnose a niggling problem with my plants.

Although my plants look a heck of a lot better than the pics of oldtimer1's, its the leaf in the middle of the 1st pic in this thread that caught my eye. Every now and again I'd see that look to the end of the leaf in oldtimer1's pics, on some of my plants.

The whole leaf apart from the end would look healthy and then at the very end of the leaf, that exact same burnt end look. I think I need to shift more air in the vegg box.

[AussieGuy]

...

Anyhow if you ever wanted to know how important Co2 is to the plants metabolism this should be all you need to see. If there had been Co2 injection in the room every thing would have been fine.

...

(check first that my balls are suitably armour plated...)

OT,

I'm going to disagree with you on this one.

114F is just over 45C. When I first started growing, I used the air replacement method for cooling (nice big fans in and out). However, during summer, there were times when the ambient air temp at 2am was well over 30C, which is above the temp canna plants like to be. Inside the room, no matter how many fans I added, temp on those nights never came below almost 40C (104F). 2 or 3 nights like that, and my plants would show the same damage as the pic in the opening post.

The inlet air had plenty of CO2. The air temp was just too high and it evaporated water from the extremities of the leaves faster than the plant could replenish it, leaving that burnt end damage all over the plant. It's heat damage from the air temp, not radiant heat damage from the lights or a lack of CO2 specifically.

AG.

[AussieGuy]

I should add that on nights like this (like most people, my day cycle is run during the night) , I ran an hourly shuttle to the local 7-11, buying bags of ice to cut open and just throw across the floor. I got to see this damage happen in front of my eyes, hour by hour.

I wouldn't disagree with OT if I wasn't absolutely certain.

[oldtimer1]

AussieGuy sorry Bish pointed out you had posted, I’m not to well at the moment. Heat/light/humidity/Co2 are horse and cart, kind of linked.

I thought I had explained it well, seems not.

Plants, like us breath, We use/take in oxygen and exhale C02 and water vapor.

Plants take in Co2 and give out oxygen and water vapor.

For a plant to be able to breath, transpire and photosynthesize it needs a constant supply of Co2 to drive the system, it relies on air movement over the leaf surface to exchange air and water with the surrounding air mass. Outdoors even when the air is still, its constantly moving there is a constant exchange of humidity and gas with the leaves and surrounding air, as long as it is not at dew point, enclosed within a cabinet this is not the case, the air is the volume enclosed, free exchange is restricted to the enclosed volume. So we are in charge of replicating as closely as we can the dynamics of the outside atmosphere.

We pack plants in the enclosed volume, we supply the Co2 the plants need to breath and metabolize, we have air exchange to supply fresh air and circulating fans to distribute the air through the canopy and across the leaf surfaces, as a general rule of thumb we say change all the air in the room every 3 to 5 minutes, this holds good for maximum growth if the temperature, humidity and light level in the room are within certain parameters.

90f is round the upper limit for good metabolization at atmospheric Co2 norm [about 350 ppm] in well lit conditions, above this temperature, respiration and growth slows even where there is good air circulation. This is compounded by the fact that as temperature rises, air can hold more water vapor, if the room air can hold 200 g of water for a given volume at 10c it can hold 400g at 21c and 800g at 32c. The more water the harder it is for the plant to make good gas exchange. So the warmer it is the more important air circulation through the leaves becomes.

While we are on how much water the air can hold, its important that ventilation is maintained in the dark period, if ventilation is shut down at lights out, as the temperature drops the moisture the air holds has to go somewhere and we don’t want it condensing on the plants.

Add or raise the Co2 level to round 1500 ppm and plants will grow happily up to 40c, at 2000 ppm up to 50c, getting it right at these temperatures and controlling air moisture though is another thing, it is critical that water is constantly available so that turgidity levels are optimum. One small mistake and your plants are dead, its best to use computerised environmental controls, thats beyond most cupboard home growers or ever really needed in the uk.

AussieGuy in a ventilated enclosed environment 300 or 350ppm of Co2 is not adequate with the sort of temperatures you are talking about even with hydro keeping the plants turgid.

I’ve seen people growing indoors at constant 40 to 42c daytime ambient, 60kw of lighting Co2 cycling between 1500 and 1800 ppm, part sealed environment, air flush once an hour, humidity and temperature controlled via air con with no problems at all, these were their optimum yield parameters.

In my little room all the fans were shut off for two days, both ventilation and circulation fans, of course the heat caused the damage, but only because the plants could not breath, ie a lack of Co2. Cannabis stops growing at about 200 ppm of Co2 at 80c. I think the only reason plants survived is its a leaky old victorian house and the ventilation ducts worked like a chimney.

If you were put in a sealed room, once you had used up the oxygen to below the level you need to continue metabolizing, being cold or warm may alter the time it takes, at the end of the day you would die of oxygen starvation.

Things that might help you, in a warmer climate than here, if you want to stick with conventional ventilation you could try running your input air through a big swamp cooler and also use smaller swamp coolers for air circulation. Friends of mine have done this in the southern US states quite successfully.

Or use aircon + Co2 with shut down periods for the air exchange, I know people who run totally sealed, but they often run into bad gas build up and fungal probs. I think I would go the aircon route if I lived in a hot climate, it also gives a good supply of pure water.

Hope this helps Ot1.

[AussieGuy]

AussieGuy sorry Bish pointed out you had posted, I’m not to well at the moment. Heat/light/humidity/Co2 are horse and cart, kind of linked.

I thought I had explained it well, seems not.

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etc

Goodness me, how condescending.

OT, you said the damage occurred while you were away. I thought I'd share with you the experience of seeing that particular damage happen in front of my eyes (not while absent) and what caused it. Plenty of CO2, lots of air movement, but too much heat in the air.

Saving on the verbosity:

- Hot air evaporates moisture from leaves

- There's a limit to how fast a plant can replace evaporated moisture in a leaf

- Plant metabolic rate only has a minimal impact on this limit

- The evaporation rate when you're over 40C is too high for the plant to deal with

- After a couple of days of this kind of abuse, the ends of the leaves dry out completely due to lack of moisture

- Keep it up for more than a week and no amount of CO2 will save your plants. They'll eventually die.

Saw it happening, touched the leaves, felt the changes from the loss of moisture. You might theorize that an increased CO2 level would have saved your plants via improved metabolism, whereas adding CO2 enrichment to the overheated air scenario only hastened the damage in practice.

AG

[oldtimer1]

I’m sorry if you think I’m condescending, it was not meant like that.

Cannabis and many other plant grow outdoors in areas where the day temperatures are between 40 and 50c and sometimes far in excess of that day after day for weeks on end with no damage whatsoever. How do you explain that?

Commercial growers get optimum returns at round 40c ambient in grams per w with Co2 enrichment.

Observing somthing first hand is only of value if you understand what is happening and why.

[AussieGuy]

I’m sorry if you think I’m condescending, it was not meant like that.

Cannabis and many other plant grow outdoors in areas where the day temperatures are between 40 and 50c and sometimes far in excess of that day after day for weeks on end with no damage whatsoever. How do you explain that?

I'm not an outdoor grower and have no opinion whatsoever about anything happening outdoors.

But, uhh, out of curiosity, can you tell me which area has temperatures far in excess of 50C for weeks on end? Are we talking the middle of the Sahara or something?

Commercial growers get optimum returns at round 40c ambient in grams per w with Co2 enrichment.

Observing somthing first hand is only of value if you understand what is happening and why.

This problem was a recurrent nightmare for the first 3 summers I was growing. After the first (when I'd been growing for about a year) I knew enough about plants and biochem to reach the same conclusion as you've posted - that CO2 enrichment would resolve the issue. I set up an air treatment room as an intermediary between the outside air and my room intakes, and enriched the inlet air in that treatment room with CO2. Over that summer and the next, I gradually increased the amount of CO2 being injected into the inlet to resolve the issue. I worked upwards in steps of 100ppm CO2 until I reached 1700. The impact was that the rate of damage increased.

After the 3rd year of this problem damaging my plants, I junked the air treatment room, closed up the inlets and outlets and went aircon. Strangely enough, this worked, despite the fact I've never encountered the concept of closed air conditioned grow rooms in any plant biology text I've read. If I relied solely on theories, I'd never have made that step.

And my optimal environment seems to be 26C-27C, 50%-55% humidity, 1300-1500ppm CO2. That's where I get my best yields. It may be strain dependent, but after the experiences I've had, I think I'd want to actually see someone successfully growing canna plants at 75C with my own eyes right in front of me before I give that claim much credit. Commercial growers get optimal yields in optimal environments.

Theory is a wonderful thing, as is knowledge. Neither come close to experience.

[Haile_Selassie]

hi there,

Now im sure you guys have figured out the problem causing the plant to turn like that.......

But correct me if im wrong ( after all we are here to learn ) judging by the pic it also looks like Potassium Deficiancy.

Here is a little quote about potassium (K) deficiancy :

" Older leaves, first tips and margins, then whole leaves turn dark yellow and die. Stem become weak and often brittle. Plants become susceptible to disease.

K is usually present in soil, but locked in by high salinity. Internal temperature of foliage climbs causing protein cells burn and degrade. Excessive evaporation from leaf edges causes burning...."

i have looked at afew pics and yours is pretty much identical to those suffering from K deficiency....

Thats my Two cents any who........let me know if im wrong

Jah Bless

H.S.***