J
J Henry
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- 28
Writers and salesmen love to create confusion between air and oxygen, it so easy to play with words.
Air, oxygen and nitrogen all smell, taste and look the same so who will ever really know the difference without testing the dissolved oxygen saturation/concentration in nutrient solution – of course, no one will know the difference so let’s promote oxygen and sell some air pumps and air stones, water chillers and chemical antimicrobials. When you see the root rot you will know then you got a low oxygen problem that needs immediate attention or you can replant and start over.
Using air is always a major limiting factor of when continuous safe oxygenation is the point of the exercise. To escape the oxygen limitation in air, supplemental oxygen >20% is necessary. Supplemental oxygen comes in many cost effective forms. Beneficial microbes consume a lot of oxygen that you can first imagine to be healthy and some grower’s think healthy microbes are important for a RDWC eco system to be healthy and thrive. The more healthy microbes in your system, the greater the total oxygen demand, the more oxygen (not air) you must provide 24/7 else tour good microbes will surely get sick, they suffocate and die from lack of oxygen. That’s logical for most growers. What is not logical is the idea that air provides all the dissolved oxygen necessary to sustain 2 different eco systems in RDWC nutrient solution 24/7 form the seed germination to the harvest.
Check out this piece:
“Water temperature ranges in hydroponic systems” http://www.growersguidetocannabis.com/water-temperature-ranges-in-a-hydroponic-systems/
Why do we need to control water temperatures?
In a natural environment cannabis does not thrive submerged in water: it prefers alternate wet/dry climate (which we replicate with the wet dry cycle when growing in soil or coco-perlite) in order to drag [air] oxygen into its root system and thereby into the plant.
However when we start to adjust the natural order with an indoor grow room, and especially when using the highly artificial hydroponic method of growing cannabis, the plants’ root system needs careful manangement. If you plop a cannabis plant into a bucket of water it will die if left for a few days. This is because the root system will be unable to perform osmosis, and, deprived of oxygen [air] the plant will be unable to photosythesise and eventually it will wither and die.
(so why do cannabis growers use hydroponic systems? Quite simply because given the right conditions, hydroponics enable bigger, quicker results than any others. Hydroponic grows “mainline” the nutrients, water and [air] oxygen direct to where the plants can make use of them: the root system).
When growing with hydroponic systems there are a number of different ways to introduce [air] oxygen into the system. The main examples are:
So why am I talking about [air] oxygen when the subject matter is water temperature?
The temperature of water and its oxygen content are closely related, and the temperature of the solution needs to be fairly closely monitored in order to maintain dissolved oxygen levels. [most RDWC growers monitor DO by watching for root rot, a few savvy growers monitor DO with a DO Meter]
At low water temperatures, the plants go into shock, but as the temperature rises in the tank the solution loses the percentage ratio of its oxygen content. Here are some figures
tank temperature & % of oxygen in the solution (ppm) : [these ppm values are based on air exposure to the water with no concentrate in solution]
10ºc (50ºf) 13 ppm
20ºc (68ºf) 9-10 ppm
30º (86ºf) 7 ppm
As you can see the oxygen content in the resolution approximately halves for every 10ºc rise in solution temperatures. ok got that!
In easy terms, ideal temps are between 18 and 20 ºc and if your water temps are anywhere near 25 -30ºc then the oxygen levels can be as much as half of the desired levels. [these ppm values are also based on air exposure to the water with no concentrate in solution]
BUT
As a direct result of the water temperature being at higher temps the plants will need more oxygen at the roots so the problem is almost squared and there is 25-40 % less oxygen in the solution and the plants will need double the amount than normal. [these percent values are also based on air exposure to the water with no concentrate in solution]
In real terms the effect is that the oxygen level in the solution is only at 25 % of the desired levels and you can chuck as much light or feeds at them as you like but if they are only running at 25% of the required dissolved oxygen levels then this is hardly conducive to happy healthy growth is it? . [these ppm values are also based on air exposure to the water with no concentrate in solution]
Some of the results of low oxygen levels in the rez tank are: [these low oxygen problems are caused by air exposure to the water, because air simply does not contain enough oxygen to satisfy the oxygen demand]
[Supplemental oxygen administration is by far most direct, the quickest, easiest and very best way to completely prevent low-oxygen conditions and guarantee the highest quality oxygenation to insure plant and microbial health, if the grow needs more oxygen give the grow more oxygen; not more air, colder water or antimicrobial killer chemicals like hydrogen peroxide – supplemental oxygen administration is as simple and cost effective as safe oxygenation is ever going to get.]
J
Air, oxygen and nitrogen all smell, taste and look the same so who will ever really know the difference without testing the dissolved oxygen saturation/concentration in nutrient solution – of course, no one will know the difference so let’s promote oxygen and sell some air pumps and air stones, water chillers and chemical antimicrobials. When you see the root rot you will know then you got a low oxygen problem that needs immediate attention or you can replant and start over.
Using air is always a major limiting factor of when continuous safe oxygenation is the point of the exercise. To escape the oxygen limitation in air, supplemental oxygen >20% is necessary. Supplemental oxygen comes in many cost effective forms. Beneficial microbes consume a lot of oxygen that you can first imagine to be healthy and some grower’s think healthy microbes are important for a RDWC eco system to be healthy and thrive. The more healthy microbes in your system, the greater the total oxygen demand, the more oxygen (not air) you must provide 24/7 else tour good microbes will surely get sick, they suffocate and die from lack of oxygen. That’s logical for most growers. What is not logical is the idea that air provides all the dissolved oxygen necessary to sustain 2 different eco systems in RDWC nutrient solution 24/7 form the seed germination to the harvest.
Check out this piece:
“Water temperature ranges in hydroponic systems” http://www.growersguidetocannabis.com/water-temperature-ranges-in-a-hydroponic-systems/
Why do we need to control water temperatures?
In a natural environment cannabis does not thrive submerged in water: it prefers alternate wet/dry climate (which we replicate with the wet dry cycle when growing in soil or coco-perlite) in order to drag [air] oxygen into its root system and thereby into the plant.
However when we start to adjust the natural order with an indoor grow room, and especially when using the highly artificial hydroponic method of growing cannabis, the plants’ root system needs careful manangement. If you plop a cannabis plant into a bucket of water it will die if left for a few days. This is because the root system will be unable to perform osmosis, and, deprived of oxygen [air] the plant will be unable to photosythesise and eventually it will wither and die.
(so why do cannabis growers use hydroponic systems? Quite simply because given the right conditions, hydroponics enable bigger, quicker results than any others. Hydroponic grows “mainline” the nutrients, water and [air] oxygen direct to where the plants can make use of them: the root system).
When growing with hydroponic systems there are a number of different ways to introduce [air] oxygen into the system. The main examples are:
- DWC (Deep water culture)With DWC the [air] oxygen in the system is introduced mechanically through an air pump and air stone underneath the root system.
- EBB & FLOW.The tray is flooded periodically, submerging pots filled with ceramic pebbles. As the water drains through, it drags all the old [air] oxygen out of the sytem and pulls in [air] oxygen rich enhanced new nutrient.
- NFT (NUTRIENT FILM TECHNQUE)This is a system where a film of water is passed over a tray where the roots sit on a spreader mat. As the roots grow some sit submerged and others arch out of the nutrient film to reach air in a highly humid, light sealed enviroment. Some growers will also add an air stone to enhance the [air] oxygen content within the main reservoir and thereby the film of water. Dependent on the height of the trays in relation to the reservoir tank, the fall of water from the tray back to the tank can also introduce [air] oxygen. [Of course they don’t tell you that air is always 80% nitrogen and only 20% oxygen, doesn’t matter how much air you pump that all the oxygen there is in air]
So why am I talking about [air] oxygen when the subject matter is water temperature?
The temperature of water and its oxygen content are closely related, and the temperature of the solution needs to be fairly closely monitored in order to maintain dissolved oxygen levels. [most RDWC growers monitor DO by watching for root rot, a few savvy growers monitor DO with a DO Meter]
At low water temperatures, the plants go into shock, but as the temperature rises in the tank the solution loses the percentage ratio of its oxygen content. Here are some figures
tank temperature & % of oxygen in the solution (ppm) : [these ppm values are based on air exposure to the water with no concentrate in solution]
10ºc (50ºf) 13 ppm
20ºc (68ºf) 9-10 ppm
30º (86ºf) 7 ppm
As you can see the oxygen content in the resolution approximately halves for every 10ºc rise in solution temperatures. ok got that!
In easy terms, ideal temps are between 18 and 20 ºc and if your water temps are anywhere near 25 -30ºc then the oxygen levels can be as much as half of the desired levels. [these ppm values are also based on air exposure to the water with no concentrate in solution]
BUT
As a direct result of the water temperature being at higher temps the plants will need more oxygen at the roots so the problem is almost squared and there is 25-40 % less oxygen in the solution and the plants will need double the amount than normal. [these percent values are also based on air exposure to the water with no concentrate in solution]
In real terms the effect is that the oxygen level in the solution is only at 25 % of the desired levels and you can chuck as much light or feeds at them as you like but if they are only running at 25% of the required dissolved oxygen levels then this is hardly conducive to happy healthy growth is it? . [these ppm values are also based on air exposure to the water with no concentrate in solution]
Some of the results of low oxygen levels in the rez tank are: [these low oxygen problems are caused by air exposure to the water, because air simply does not contain enough oxygen to satisfy the oxygen demand]
- roots are unable to work effectively, leading to:
- a build up of toxins meaning that the plant will be unable to take up the water and feeds needed for healthy growth
- The whole plant begins to deteriorate as photosynthesis and carbohydrate rates slow leading to wilting.
- Leaf damage and root die-back. Ethylene is released and causes a toxic overdose and the roots fail.
[Supplemental oxygen administration is by far most direct, the quickest, easiest and very best way to completely prevent low-oxygen conditions and guarantee the highest quality oxygenation to insure plant and microbial health, if the grow needs more oxygen give the grow more oxygen; not more air, colder water or antimicrobial killer chemicals like hydrogen peroxide – supplemental oxygen administration is as simple and cost effective as safe oxygenation is ever going to get.]
J