PhatNuggz
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Equilibrium is equilibrium https://www.merriam-webster.com/dictionary/equilibrium
OK I have a fair bit of personal experience with Co2/O2 dissolution in water. I can give you my take but i'm going off pure memory and have no time to look this up for accuracy so please ensure to double check.
DO levels in water with no influence of uptake are determined by temperature, pressure and salinity. In our case temperature is the most influential. lower temps hold more oxygen. This biggest misconception people have is that you can add more oxygen to the water than it holds at equilibrium. Yes you can but oxygen is extremely hard to dissolve in water above equilibrium and there is no need to do so IMO. Our goal is to maintain DO levels as close to equilibrium so that we do not become deficient in them. These type of atomizers create the smallest of bubbles and the theory is the smaller to bubble the more oxygen this supplies because it has more surface area contact with the water. While is true the magnitude of it is very insignificant. Most airstones provide bubbles that reach the surface quickly due to size and buoyancy, atomizers can create bubbles that hang in the water column for quite some time not really increasing DO levels but the suspension of gas in the water (I cannot say if this has any benefit or consequence). The other negative side to an atomizer is the break down of the plates as it reacts (i believe this is due to oxidization but cannot remember for sure) and I believe releases heavy metals in that reaction. Whether or not toxic levels I cannot remember.
In terms of adding Co2 to the water with air pumps. This just can't happen (in most cases) because of equilibrium if your supply air source is the same as your grow space Co2 levels in the air are the same and have reached equilibrium therefore the only gas exchange that an air pump could contribute to is a dissolved gas that has been depleted below equilibrium.
The biggest factors we need to look at are in no particular order are:
1.Circulation of the water in our systems (Oxygen can become depleted at the top or bottom layer of water) so it key to our water mixing.
2. Surface area agitation. The largest portion of gas exchange happens from surface area agitation (remember you wont feasibly be able to add more DO than equilibrium but maintaining those levels is key) There are more ways than airstone and some are more effective than airstones however airstones also provide mixing of the water column.
3. Water temp to a lesser extent because as long as you have adequate surface area and agitation you should be good. (only speaking in terms of DO)
There are more but these are the main ones.
There are 2 types of bacteria anaerobic and aerobic. In hydro you will never have anaerobic conditions. This usually occurs in compact substrates in nature not in water columns and those types of bacteria are responsible for h2s gas that can be deadly at low concentrations.
The temps you are quoting are shoot and leaf temps I think not the roots. I would have to see the study. Transpiration is the driving force for water uptake this takes place in the leaf and is most affected by leaf temp...not root temp. Although at some point low root temp would affect this and in the studies I have read that occurs below 66f and the growth rate from 68 to 75f is not all that significant.
Exactly my thought. My understanding is that the growth of anaerobic bacteria is what causes root rot not the heat at all. Anaerobic bacteria propagates in an environment lacking in oxygen content but high in heat and aerobic bacteria thriving in a warm environment with high levels of DO.The point, I thought, was to increase oxygen content to combat the forming of anaerobic bacteria.then what causes root rot or root slime? I have experienced both when temps were too high
There are good and bad aerobic bacteria. Look at salmonella, ecoli and one that's common in hydro pythium. All of which reproduce faster in higher temps. Anaerobic and aerobic bacteria only means one requires oxygen and the other does not. It has no bearing on whether or not they are beneficial.then what causes root rot or root slime? I have experienced both when temps were too high
There are many causes of smell in water. Dying bacteria, bacteria breaking down organic matter both in aerobic conditions. Think about this why does rotting food smell? It's not because it's in anaerobic conditions. Like I said you will not come across anaerobic conditions in a water column. What you will see is low oxygen where it will negatively impact the plants processes. Due to that the root may suffer damage and bacteria will begin to feed on the decaying matter. Usually this is where pythium starts to take hold. And in warm temps very rapidly. I think you are a bit confused saying all aerobic bacteria are good and all anaerobic bacteria are bad. That is simply not the case.The definition of aerobic is good and anaerobic is bad. Anaerobic bacteria is what causes the foul smell in your water.
I'm heading out for lunch. In vegas for another week or so but I will respond to this when I get back. Great conversation for learning. But you need to remember we do not have a substrate in hydro like we do in nature or some aquariums. If you just look up where anaerobic bacteria form in both nature and aquariums you will see we do not have anaerobic conditions in hydro. Some anaerobic bacteria are also tolerant of oxygen but require high co2 it's not a black and white thing and gets complex. I am not a microbioligist but a hobbiest si I will provide the info I can on it. Sometimes it's hard for me to remember the exact explanations behind all the processes.From my research,
ll bodies of water possess a dynamic balance of microbiological activity. In hydroponics, we strive to keep the nutrient solution as sterile as possible, but nonetheless, nutrient solution is by its very nature the perfect place for things to grow. Some microbes require dissolved oxygen to live (aerobic), and others do not (anaerobic). As a general rule of thumb, aerobic bacteria are "good," and anaerobic are "bad." Put simply, the byproducts of anaerobic respiration are acids that wreak havoc with chemical and biological balances within the nutrient solution, which in turn harms the root system. Warm, stagnant water holds little dissolved oxygen, making it an ideal breeding ground for anaerobic bacteria, many of which (Fusarium, Pythium) cause crop failure as they take up home in the fragile root system and proliferate. The foul smells associated with warm stagnant water (sewers, swamps) is caused by these "bad" bacteria. Methane gas (swamp gas) is a highly flammable "natural" gas that is also a byproduct of anaerobic bacteria. Can you see how, left unchecked, these bacteria can ruin a crop? Rampant pH swings, swampy smells, root rot and ultimately crop failure are the tell tale signs of a poorly balanced biology within your system.
Few min waiting for the other couple. The biggest reason you will never see anaerobic condition in hydro is the water is not stagnant, there is no substrate and thus is important because it's usually a compact substrate that causes no water to flow through it and thus the aerobic nitrifying bacteria consume the small amount of oxygen at the surface layer and just beneath the anaerobic nutrifying bacteria use a different process and give off h2s as a byproduct. Our hydro systems have more than enough flow, gas exchange to prevent any anaerobic conditions. The smell is bacteria breaking down organic matter and dying bacteria.From my research,
ll bodies of water possess a dynamic balance of microbiological activity. In hydroponics, we strive to keep the nutrient solution as sterile as possible, but nonetheless, nutrient solution is by its very nature the perfect place for things to grow. Some microbes require dissolved oxygen to live (aerobic), and others do not (anaerobic). As a general rule of thumb, aerobic bacteria are "good," and anaerobic are "bad." Put simply, the byproducts of anaerobic respiration are acids that wreak havoc with chemical and biological balances within the nutrient solution, which in turn harms the root system. Warm, stagnant water holds little dissolved oxygen, making it an ideal breeding ground for anaerobic bacteria, many of which (Fusarium, Pythium) cause crop failure as they take up home in the fragile root system and proliferate. The foul smells associated with warm stagnant water (sewers, swamps) is caused by these "bad" bacteria. Methane gas (swamp gas) is a highly flammable "natural" gas that is also a byproduct of anaerobic bacteria. Can you see how, left unchecked, these bacteria can ruin a crop? Rampant pH swings, swampy smells, root rot and ultimately crop failure are the tell tale signs of a poorly balanced biology within your system.
Pythium grows in anaerobic conditions
Pythium is not really caused by anything. In a living medium not sterile. You just increase risk factor and how rapidly it can reproduce. If you plant is in top top shape from seed to harvest it's unlikely you will see any problems. But increase the preferred environmental factors like temp, low oxygen and then add a bump in the road and you are a lot more likely to see pythiumWhat I'm confused by is if pythium is caused by anaerobic conditions than how is there no anaerobic bacteria in the system when you get pythium?
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