If you have chemistry questions....

[squiggly]

hey forknowledge, i'll jump on this one . . . 'hope squiggly doesn't mind.

I certainly don't mind. In this thread, you should be sure of the information you are providing. I have been very careful to not provide information that I do not have expertise in without the added caveat that I can't say for certain. If everyone follows a similar process, we will all come away enriched. That's all I ask of anyone, beyond that--share your wisdom with us, by all means!

On to the meat:

Okay this is a tough question--because it's an argument which can be drawn out to extremes.

In terms of actual dissolved oxygen, no--this won't cause an issue and will likely increase yields as suggested.

However, it is possible to have too much oxygen throughput. This can mess with absorption, and can oxidize some macromolecular nutes that you may have applied. It won't usually do anything to your simple ions.

A good example of what "too much oxygen throughput" might look like can be seen here:

As I said, this is on an extreme end of the spectrum. With this much oxygen moving through (and with small bubble size--also important) you could potentially start to precipitate out some of your nutes, especially if you use any powders.

For most purposes, this shouldn't pose a problem.

Papa also brings up a great point--a bigger pump with the same stone is not likely to give the best results (though it could under some circumstances). You could end up accelerating the bubbles towards the surface faster and actually reducing your DO.

The smaller the bubbles the less this matters.

Oxygen is oxidative, as you might imagine, and that can cause problems for your bennies if DO levels are too high--but by and large this shouldn't cause issues. As for the plant, you might see some oxidative stress on the roots at maximized DO levels, but nothing visible--and frankly because of the lifespan of the plant (less than a year) oxidative stress is not a huge issue. The plant will kill itself long before oxidative stress will give it cancer or erode its biological systems.

 

[kushtrees]

Is there a good formula to size an air pump depending on water volume, depth, air stone type/ size (this is a tough one) and distance from pump to stone?

I'm working on a SWC and am getting tired of trial and error to find the right air stones/ pump

I know there are a lot of variables involved but a good starting point would be great

 

[SodaLicious]

Hey squiggly what , if any, information do you have or know on the use of activated carbon for filtering concentrates?

 

[squiggly]

Hey squiggly what , if any, information do you have or know on the use of activated carbon for filtering concentrates?

It would likely remove most of your terpenes. It's going to also remove stuff with a net negative charge. It would almost certainly take out most pigments--like anthocyanins and such.

Worth checking out if you have the know how I suppose--because I can't guarantee any of this.

I imagine it would be useful for processing crude extracts--but I'd almost sooner go with graywolf's winterize/filter/brine wash method.

 

[squiggly]

Is there a good formula to size an air pump depending on water volume, depth, air stone type/ size (this is a tough one) and distance from pump to stone?

I'm working on a SWC and am getting tired of trial and error to find the right air stones/ pump

I know there are a lot of variables involved but a good starting point would be great

Im sure there might be, but now we're into the physics zone--and while I implicitly understand much of what physics has to offer, I'm notoriously bad with the numbers and equations--otherwise I'd be a chemical engineer and have better job prospects and a more favorable financial outlook.

 

[caveman4.20]

Squiggly do you ever use a water pump instead of air pump? For instance breaking the surface of the water by pumping water above surface and returning the water with a shower head type end so ther are many streams breaking the surface of water like a shower waterfall?

 

[squiggly]

Squiggly do you ever use a water pump instead of air pump? For instance breaking the surface of the water by pumping water above surface and returning the water with a shower head type end so ther are many streams breaking the surface of water like a shower waterfall?

No I don't personally, and that probably wouldn't be as effective--but it would work for exactly the reasons you point out.

You'd almost do better just creating a vortex in the water. The swirling pulls air into the water which is a pretty dang effective way to oxygenate water. It was recently found that the oceans do something like this (which is why they think CO2 dissolution in the ocean is going up faster than they expected it would).

 

[caveman4.20]

What about electrolysis is that an effective way to oxygenate reservoir?

 

[squiggly]

What about electrolysis is that an effective way to oxygenate reservoir?

No, you'll make hydrogen gas and explode yourself.

 

[caveman4.20]

There's no way to vent that out somehow just let me know if I'm dumbing down the thread ill stop throwing suggestions out there hey I wanted to ask where I can find your grow logs I probably asked before but forgot.

 

[squiggly]

There's no way to vent that out somehow just let me know if I'm dumbing down the thread ill stop throwing suggestions out there hey I wanted to ask where I can find your grow logs I probably asked before but forgot.

Not safe. Hydrogen is insanely explosive.

I don't have a grow log. I'm in a non-med state and wary of such practices.

 

[caveman4.20]

Oh ya that sucks good luck with everything peace

 

[forknowledge]

Thanks papa & squiggly.

papa, I should have mentioned that ive built my own DIY UC system & Im using 2 air stones per tub/plant. Sorry about that.

I should probably be asking is it essential to consider the amount of the air pump pushes through the entire system as opposed to how much is dived per tub/plant?

squiggly, thanks for the vid, I dont think a 120L per min will be a problem so Im going to give it a try when I expand my system to 6 sites.

Thanks very much both of you.

 

[woodsmaneh]

Dissolving more oxygen into hydroponic solutions could boost greenhouse productivity and provide a whole host of other benefits too, say University of Guelph researchers.
Prof. Mike Dixon and Dr. Youbin Zheng, Department of Environmental Biology, are investigating the positive aspects of using an oxygen diffuser to increase oxygen levels in greenhouse hydroponic solutions used to grow roses, tomatoes, cucumbers and peppers.


Dr. Youbin Zheng, Department of Environmental Biology, is studying if oxygen levels can be boosted in hydroponic solutions to help growers ward off harmful microbes and boost productivity.
Preliminary results suggest a higher dissolved oxygen level increase productivity, health and root vigor in greenhouse plants, and helps keep harmful microbes in check. “These findings are really beneficial to the industry,” says Zheng. “If we can use oxygen to boost plant health, making them stronger and more resistant to disease, we've discovered a very helpful tool.” Oxygen isn't as prevalent in warm water as in cool water, so oxygen levels tend to be low -- about two to four parts per million (ppm) -- at high greenhouse temperatures, compared to eight to nine ppm in cool water. Under hot weather in the greenhouse, the root zone is especially short on oxygen, says Zheng, because root respiration depletes oxygen in hydroponic solutions. Excessive watering can further depress oxygen levels because it makes growth media, such as rockwool or coconut fibre, less porous, blocking air. These factors all weaken plant disease defense systems, making them more susceptible to disease-causing microbes such as Fusarium and Pythium which cause root decay. To prevent this problem, greenhouse growers typically bubble air into hydroponic solutions to bring oxygen levels up to about nine ppm. But sometimes this still isn't enough. Two years ago, the BC Greenhouse Growers' Association asked Dixon to investigate using even higher oxygen levels in hydroponic solutions. His literature review revealed that very little work had been done in this area suggesting the problem was largely ignored – until now.
Dixon and Zheng are using an oxygen diffuser recently developed and manufactured by Seair Diffusion Systems Inc., an Edmonton-based company with an interest in the greenhouse sector. The diffuser concentrates atmospheric oxygen, and dissolves it into hydroponic solutions. With this technology, oxygen levels can reach as high as 60 ppm in hydroponic solutions.
The research team is currently studying the effects of different oxygen levels, ranging from about nine ppm to 40 ppm. So far, preliminary results are promising. But creating optimal supersaturated oxygen solutions requires extreme precision. Oxygen can be damaging at very high levels, says Dixon , so it's important to establish application methods for using this technology for different crops. But if the methods can be worked out, Dixon says the oxygen diffusers are inexpensive and stand to emerge as an economical, environmentally friendly solution for growers looking to enhance their crops. “Greenhouse growers are voracious technical consumers – they'll try anything,” says Dixon . “But by the same token, they're also very shrewd business people, and they won't waste money unnecessarily.” Dixon and Zheng will continue their research and will further investigate oxygen's effect on plant growth, physiology and disease. For example, they will inoculate greenhouse plants with specific microbes to see how the plants cope with this challenge under different oxygen levels. Other researchers involved in this project include technician Linping Wang, graduate student Johanna Valentine and undergraduate student Mark Mallany, Department of Environmental Biology. This research is being conducted at greenhouses in Guelph and Leamington , Ontario . It is sponsored by Seair Diffusion Systems Inc., Flowers Canada Ontario and the Fred Miller Rose Research Fund.

 

[We Solidarity]

yo squiggs - got a question for ya.

everytime I try to do research on chelation, nutrient uptake, and polarity I always wind up in some equation or post-grad research paper that is completely over my head. Is there a simple way to describe what chelation does to nutrient ions to make them available to plants? And what elements/nutrients/molecules can/need to be chelated?All a topic i am very curious about...

 

[caveman4.20]

Moderator status NICE! Good call Logic.

 

[caveman4.20]

yo squiggs - got a question for ya.

everytime I try to do research on chelation, nutrient uptake, and polarity I always wind up in some equation or post-grad research paper that is completely over my head. Is there a simple way to describe what chelation does to nutrient ions to make them available to plants? And what elements/nutrients/molecules can/need to be chelated?All a topic i am very curious about...

Great question and too add how does that differ from organic chelates.

 

[squiggly]

Moderator status NICE! Good call Logic.

Thanks dude.

yo squiggs - got a question for ya.

everytime I try to do research on chelation, nutrient uptake, and polarity I always wind up in some equation or post-grad research paper that is completely over my head. Is there a simple way to describe what chelation does to nutrient ions to make them available to plants? And what elements/nutrients/molecules can/need to be chelated?All a topic i am very curious about...

Alright this can get pretty messy fairly quickly. It's an advanced topic and I'll start by saying that I'm not going to be able to tell you, with brevity, the most interesting stuff about this scientifically. That said:

Okay so in reactivity studies we are often concerned with charge. Things associate based on charge in chemistry. Opposites attract, like charges repel--all that fun stuff.
Typically we think of the electrons as doing the work in chemistry, but this is really just by convention. It's all physics at play really.

So we have a substance with a negative, or partial negative, charge. A common example would be a dissociated carboxylic acid:

The first two structures above are what are known as "resonance structures" they are a way for us to keep track of charge in chemistry. The right hand molecule is the "real" version of the molecule--the negative charge is shared by the two oxygen atoms rather than interchanging between them as in the first picture. The first two molecules are 100% fake representations.

Let's say that this compound is in a solution with some metal ions.

There are two concepts which must be introduced:

1. Coordination complexes

In our hypothetical solution the positive ions will tend to associate with the negative end of this carboxylate group. This forms what is known as a coordination complex:

In the above picture the central atom is a positively charged ion. There are 3 identical molecules of C2O4 (2-) chelating this molecule. These molecules are called chelants, or chelating molecules.

2. Denticity
You will also notice in the above coordination complex that each molecule of C2O4(2-) is contributing 2 coordinate covalent bonds (these are different from covalent bonds and not as strong as either covalent or ionic bonds).

These are thus polydentate ligands. The standard for chelation as a process is that it occur between an ion and a polydentate ligand [as opposed to a monodentate ligand].

Chelation occurs when:

A complex is formed between an ion and a polydentate ligand consisting of two or more coordinate covalent bonds between the species.

Reasons for chelation:
Some chelants allow molecules to more easily permeate membranes. They do this by tucking all of the polarity on the inside of the complex--and they leave a non-polar face on the outside, creating a molecule which can easily permeate a membrane (polar molecules do not cross membranes easily--this process essentially packages the polar element of the molecule inside a non-polar package).

Other chelants are intended to prevent precipitation. For instance, calcium ions love to form insoluble compounds with negative ions. Either chelating the calcium ions or the negative ions which they want to react with can prevent this precipitation from occurring.

Chelation makes the ion inaccessible for further reaction and there are many applications:

To prevent spoilage. Iron ions notoriously cause food spoilage (I wont get into the whys of this here). The addition of EDTA (which I challenge you to not find in 20 or more products in your home), a polydentate ligand, chelates the iron and prevents it from taking place in the reactions which cause spoilage.

Chelation is used in heavy-metal poisoning therapy. The blood is titrated with a chelant which forms a coordination complex with the metal (preventing it from reacting further in the body) which can then be filtered out by dialysis.

The list goes on and on.

Most of the work I do in the lab in fact depends on the concept of chelation.

What I do is form asymmetric coordination complexes. Except my purpose is not to prevent covalent attachment to the molecule--but rather to "block" one side of the molecule being reacted such that the angle of attack on the molecule is forced to come from one side.

This allows me to get the version of the molecule that I want, right or left handed.

Molecules can present this right or left handedness the same as our hands do. They have all the same components hooked up, but they are non-superimposable mirror images of each other. This means if we place them palm to palm they have symmetry about the intersection of the palms--but we cant place them palm to top of hand and make them fit, they are backwards of one another.

If we think of something called a prochiral carbon it basically looks like a carbon atom with three things jutting out from it equal distances a part. The 3 attached atoms are at the vertices of an equilateral triangle.

When a 4th atom is attached it will come from either above or below the plane of this triangle. This is because electron density likes to be as spread out as possible in a molecule and so the atoms attached to a central carbon want to be as far from one another as possible (hence the triangle for 3 and a tetrahedron for 4).

When the "attack" happens from the 4th atom the 3 original atoms "bend down" like a tripod.

it goes from this:

known as "trigonal planar" geometry, to this:

which is a tetrahedron.


So most of what I do in the lab is trying to find ways to grab molecules so that I block one side of the trigonal planar molecule in the first photo. So that I force the reaction to happen from one side.

I can control which version i make by altering the molecule I do the grabbing with (because this molecules ALSO has a right-left handedness characteristic, known as chirality).

That's a bit off topic now, but it tied in to my actual work--so I thought I'd share.

 

[ftwendy]

I just noticed that, too. Congratulations bro!

 

[We Solidarity]

that's SO awesome - so chelates are what keeps the ion neutral and allows it to pass through the casparian strip, as opposed to the plant having to synthesize a cation/anion to bond the ion and allow it to pass through the plant...correct?

and in that regard ~ can you think of any chelates that the plant can readily use once it's been absorbed? I've been pretty convinced lately that if you can provide a stabilize rhizosphere and a standardized nutrient salt regimen, you would see very very good results with amendments of different acids and horomones in different stages to act as chelates.

and another question - do nutrient salts come to us already chelated? or are they actively being chelated either in the rhizosphere or by our plants?