Recommendations please!!

[shawnery]

It's so interesting how different crops roots require different environmental factors. How they react to and how many ppms of chlorine are also very different.

I've read this one I think, nice!

 

[rkymtnman]

It's so interesting how different crops roots require different environmental factors. How they react to and how many ppms of chlorine are also very different.

I've read this one I think, nice!

that was pretty interesting: a 2C difference in root temps made a big difference in 2 fairly similar crops: lettuce and spinach.

 

[Keesje]

i did read it. i'm saying that the dog bowls are not connected.

if dog 1 can eat 500g a day and lose weight but dog 1 if given 800g a day would maintain weight, than 500g is not enough food for dog 1.

same thing with clone A, if given 8.6 DO and it grows at x rate. if clone B, if given 10.2 DO would grow at x rate then the DO would not matter since they both are growing at x rate.

but if clone B grew at x+y rate because of more DO, the the level of DO for clone A is not enough and the plant could use more DO.

either way, post a scientific study and i'll be glad to read it. i don't think there is one for cannabis. a study about lettuce is meaningless.

You did not read it well.
Bowl A can contain 500 gram.
The moment the dog eats 200 gram of it, there is 300 grams left.
But at that moment from a huge reservoir with 100 tons of dogfood the bowl will be filled up with another 200 grams, and then there is 500 grams in the bowl again.
So no matter how much the dog eats, there is always plenty of food for him.
If the dog decides to eat from the other bowl which holds 800 gram, it also can eat as much as he wants.
When he eats 350 gram, down comes another 350 gram from the huge reservoir. And the bowl will contain 800 gram again.

Sure, if the dog eats 2000 grams a day it will get fatter then if it will eat 1000 grams a day.
But it is up to the dog how much it wants to eat from the endless reservoir.
Same with roots. You can't force a root to absorb more oxygen, just by pushing more oxygen to the roots.
They can only absorb a certain amount of DO per hour. And as long as this amount of DO is around the roots, it is all ok.

Scientific study?
It is basic biology and physics.
It has nothing to do with Cannabis or Lettuce.
Roots absorb oxygen, either in gaseous state or as DO.

How much they absorb is plant specific of course. The same with nutes, CO2.
But even if Cannabis would absorb more oxygen per kilo roots, it still would not matter, because there is an endless amount of oxygen in the atmosphere.
Water at a certain temperature contains a certain amount of DO. That is a fact.
If somehow DO gets absorbed by fish or roots, the oxygen level will get back to its maximum because of atmospheric pressure.
That is a fact.

Of course in normal circumstances.
Not when the water is 50 degrees C or when 30 fish swim in a bucket of 10 liter.

 

[rkymtnman]

Scientific study?
It is basic biology and physics.
It has nothing to do with Cannabis or Lettuce.
Roots absorb oxygen, either in gaseous state or as DO.

read the Cornell study and then post one that shows what the optimal DO level for cannabis is.

lettuce and tomatoes each grow better with differing DO levels. cannabis would be no different.

How much they absorb is plant specific of course.

that's exactly my point. which you are overlooking.

 

[Keesje]

No, I am not overlooking it.

Of course some plants need more oxygen then others.
But the fact that no matter how much DO a root wants, there is always enough DO for the roots in the water.
No matter if the water is 18 degrees or 28 degrees.
If the roots want 100 mg per hour... fine.
If they want 1000 mg per hour, also fine.

The root temperature is not only about the amount of DO it can hold.
Every plant has a sweet spot where metabolism works best.
According to Cornel it is 25 degrees for tomatoes and 22 degrees for spinach.
It doesn't mention anything about the DO levels.

 

[shawnery]

Just a heads up but in hydro the DO levels are highly effected by the ec/nutrient level as well.

 

[shawnery]

Keese,

Everyone is still looking at this from a perfect enviroment which this is not. There is not always enough oxygen given certain environmental factors which in hydro have to be considered.

Ec level
Size of roots
Water agitation
Bacteria
Algae

There are so many things that can drain a system of the required DO levels that a statement like, there is always enough oxygen, could never be applied to all situations.

 

[Keesje]

Of course there is not always the same amount of DO.
There is also less DO in seawater then there is in sweet water.

But if you run a system in a normal way, there is always enough DO for plants in temperatures between 5 and 30 degrees Celsius.
If you fuck up your system with bad bacteria, yes then perhaps there will also be not enough DO.
If you not agitate your water a bit, there will also be perhaps not enough DO.
If you have huge roots and a tiny reservoir, there will also not be enough DO.
But if you fuck up all those things, DO is not a thing to worry about anymore.
Then you are fucked anyway.

Besides, these are nonsense arguments.
It is like me saying a "600 HPS gives more light then a 400 HPS"
And you'r reply is "Not if the 600 HPS is broke"

 

[Keesje]

read the Cornell study and then post one that shows what the optimal DO level for cannabis is.
Lettuce and tomatoes each grow better with differing DO levels. cannabis would be no different.

I did read the Cornel research as I was wondering on how they determined the right amount of Oxygen for every plant specific.
Because it would be the first time I ever would read about it, or even heard about it.
It would be groundbreaking news in the agricultural world.

And (not) to my surprise... they do not say this at all. Not at all.
They just say that below a certain point - 3 ppm - some plants will get in trouble, so better make sure you stay above that.

They even state the absolute opposite...
Here is some part from the paper.

Eleven day old lettuce seedlings were grown for 24 days under various DO concentrations: sub-saturated, saturated, and super-saturated. There was no significant difference in fresh weight, shoot and root dry weight among the following DO concentrations: 2.1 (25% of saturated at 24°C), 4.2 (50%), 8.4 (saturated), and 16.8 (200%) mg/L. The critical DO concentration for vigorous lettuce growth was considered to be lower than 2.1 mg/L. Neither root damage nor delay of shoot growth was observed at any of the studied DO concentrations.

Here you can read that it does not matter for lettuce on how much DO there is in the water. As long as it will not get below 2.1 mg per liter.
And yes, this is about Lettuce. Maybe for strawberries it is higher or lower. Maybe for Cannabis it is higher of lower.
But Cannabis is not like a Unicorn or some special species only to be found on the top of the Mount Everest or on the bottom of the oceans. It is a very common plant that shares a lot of properties and characteristics with other plants.

 

[rkymtnman]

It is a very common plant that shares a lot of properties and characteristics with other plants.

I agree.

But trying to extrapolate that what is good for something similar i.e. tomatos is good for cannabis is merely an semi-educated guess.

My final point since this argument is going nowhere is that until there is a cannabis specific study for DO levels, everybody is just guessing. There could even be a difference that sativas prefer more or less DO than indicas to further muddy the waters.

@shawnery : if you do rent that DO meter, please post a journal ! i'd be interested to see what you find.

 

[Keesje]

This argument is going somewhere.
Cornel says nothing about what the ideal DO for a specific plant is.
Your claim that Cornel said that they found out that lettuce and tomatoes each grow better with different DO levels, is incorrect.
They don't state it in their research paper. You misunderstood.
Or otherwise, please point it out for me where it says so.

Besides, even a plant that needs less DO, simply would absorb less from the available DO.
If it needs more, it absorbs more.
It is science, not an opinion.

In the air is always more then enough oxygen, so claiming that you have to provide plants with less or more oxygen is scientific nonsense.
The fact that some people don't understand this, is the reason that growers on this forum sometimes take measures which are unnecessary and expensive.

I don't know how much DO Sativa or Indica need exactly.
As Cornel does not know how much DO spinach needs.
But that's is not the discussion.
The discussion is that under normal circumstances in hydro there is always plenty of DO available to suit needs of the roots.

 

[Billy Liar]

I have constant DO monitoring on my system.


I'll be conducting some experiments this coming year with elevated (super saturated) DO levels. At the minute my system runs around 105% saturation.
My friend has already conducted his own experiments to the point of dissolved oxygen being toxic to the plants. His findings are that elevated DO levels are beneficial to growth.

Peace
BL

 

[rkymtnman]

I don't know how much DO Sativa or Indica need exactly.

now you are getting my point. you don't know. and neither do i.

 

[gr865]

now you are getting my point. you don't know. and neither do i.

All you have to do is move the water, don't need a shit load of stones or super saturation. Consider a stream, constantly moving over pebbles, soil, sand and the such keep a steady O2 level. Moving water in your rez for drain to waste coco is simple a small pump inside just to move the water provides plenty of O2 to the plants, IMHO

 

[rkymtnman]

All you have to do is move the water, don't need a shit load of stones or super saturation. Consider a stream, constantly moving over pebbles, soil, sand and the such keep a steady O2 level. Moving water in your rez for drain to waste coco is simple a small pump inside just to move the water provides plenty of O2 to the plants, IMHO

i agree with you GR but we were getting a bit more technical to see if cannabis would do better with x amount of DO vs y amount of DO. there just aren't any studies that show what levels of DO are minimal, acceptable, optimal and detrimental.

lettuce can grow in very low DO enviros whereas tomatos would die at those levels. and there are studies that prove this.

anywho, how you been my man?? have a good Turkey day?? mother in law was in town for me which was a bit of a drag.

 

[gr865]

i agree with you GR but we were getting a bit more technical to see if cannabis would do better with x amount of DO vs y amount of DO. there just aren't any studies that show what levels of DO are minimal, acceptable, optimal and detrimental.

lettuce can grow in very low DO enviros whereas tomatos would die at those levels. and there are studies that prove this.

anywho, how you been my man?? have a good Turkey day?? mother in law was in town for me which was a bit of a drag.

Thanks man,
I been OK, wellness amounts of FECO have been good to me. Well went to my son's mothers for T-day, it was ok, had my lady, my son and my G-kids there so it was all good.
Had a great experience recently, son an I went to the panhandle of Florida after the storm to feed people. It was quite the experience and we plan on doing it for every hurricane from now on. We were there for about 15 days, till we totally ran out of food. Was a bit depressed after returning, a bit of PTSD from all the destruction and sadness. But got back on the oil and doing much better now.
Next trip to CO I will contact and hopefully we can have a sit down.

When I was getting my degree in agronomy, I was working at the Turf grass research facility. One of the grad students work on a project to determine if the levels of O2 increased turf grass growth. We had three ponds on the facility plus city water.
The results showed that as long as there was a decent supply of 02 in the water all was good. One pond had no movement except from the air blowing over it, one had a pump that rolled the water and one had a column of air bubbles rising from it. The best results was from the pond with the rolling water, 2nd was city water, and the other two were about the same. We measured plant density, rooting, and growth rate.
I have tried the air stones and it caused my pH to rise way fast and the EC to fluctuate (mostly up). I now use a small pump in my rez to just move the solution, 1 minute every 3 hours hours during lights out and for one minute prior to the start of each irrigation cycle.

So far so good.

Just my 2.5 cents!

GR

 

[bird mcbride]

I prefer cloning bins, or like mini-greenhouse. I've used 1-2.5 gallon plastic containers for mini cloning bins for three to eight clones. I cut the top off and use a clear plastic bag for the top. I can raise the bag up a bit on the container if necessary.

I suspend about 40-80 watts cool white CFL over the mini bin.

A larger bin is made with a large clear plastic garbage bag. I suspend it on a shelf made af plywood of appropriate size and suspend a dual 4' cool white florescent on the ceiling above the bin.

These bins need the air/drain hole at the lowest point in the bin and a single layer of pebbles for drainage. The larger garbage bag style needs about three loonie size drain/air holes and the smaller one's about a loonie. With the smaller one's I punch holes in the bottom of the jugs as well as the main air/drain hole.

The problem with those purchased humidity domes is the have the air hole(s) on top. This is no good. The adjustable air slots are a good idea though because then the bin can be adjusted for the surrounding climate. On damper days I leave the door open a crack for bits at a time, depending. In some places no dome or anything is necessary because the humidity is already high, like London in the foggy season, for example.

Now I use little slivers of the soft Rockwool and simply bank them with clay gravel for suspension. A bale of this stuff will last a life time and the soft stuff wouldn't interfere with aero, soil, F&D, Coco. DWC, if it were kept to a minimum. I use to use the hard stuff but that's gone up in price and there isn't any real advantage other than easier to use. All clones have to be removed from the bin or the lid or door opened when the clones are rooted.

TBH, I can't afford failures and that's why I keep it simple. The cloning bin is in with the mother's so if their light fails they will still get some light from the Moms and in winter months being higher up would be the last to freeze in the event of a blackout.

Marijuana roots need air and they can't stand 100% saturation for more than 15 minutes. Some hybrid strains will root in a glass of plain water and can tolerate higher water saturation levels. This is also determined by elevation as well. There are so many ruling factors that there is no finite answer to your question.

 

[Keesje]

lettuce can grow in very low DO enviros whereas tomatos would die at those levels. and there are studies that prove this.

You don't understand the research paper that you came up with yourself.
It says nowhere in this Cornel research that this is the case.
Show it!
Give me the paragraph were it says so.

Now you just keep on giving false information.
Which I don't think you do on purpose, neither are you a troll.
Sorry to say, but you apparently do not understand the information given by the Cornel paper.

As long as you keep the temperature of your water between a certain range, and keep the water moving a bit, and have enough water available (relative to the roots) you never have to worry about enough DO for your roots.
It is the case for tomatoes, lettuce, spinach, cannabis, whatever.

 

[Keesje]

All you have to do is move the water, don't need a shit load of stones or super saturation. Consider a stream, constantly moving over pebbles, soil, sand and the such keep a steady O2 level. Moving water in your rez for drain to waste coco is simple a small pump inside just to move the water provides plenty of O2 to the plants, IMHO

If you use drain to waste, you don't need water with DO.
(There will be DO in the water anyway the moment you start pumping it)
But the roots in a drain to waste system get most of their oxygen in a gaseous state.
The roots get wet and only wet roots can absorb oxygen.

Compare it to growing in soil.
You feed your plants with water. The DO in that water is gone in minutes. After that it is just dead water.
The roots however keep on absorbing oxygen. Oxygen that reaches the plants through all the tiny spaces between the soil.
Oxygen in gaseous state that reaches the wet roots and thus can be absorbed.
That is also why you can drown your plant in soil, rockwool or cocos. If the medium gets totally wet, the roots will first absorb all the DO in the water. The water will be dead after that.
Oxygen from the air (gaseous state) can not reach the roots anymore, because the dead water is blocking it.
As there is no water surface (at least not a big one) so the pressure from the atmosphere can not 'push' oxygen in the water.
Result is that there is a big chance that your roots and plants die because of lack of oxygen. Or not die, but slowing down.
Only after the water has run off or has been absorbed, there will be again appear small spaces and holes in the soil where oxygen in gaseous state can flow from the air to the roots.

Moving the water in your rez (for drain to waste) now and then is a good idea hoewever.
But not for getting DO in the water, but for keeping your nutes evenly spread in the water.

 

[Keesje]

Marijuana roots need air and they can't stand 100% saturation for more than 15 minutes.

What do you mean by this?