Keesje
Well-Known Member
How did you put an air stone in an ebb&flow system?
First Ebb & Flow
- Thread starter Lazyeye1
- Start date
Keesje
Well-Known Member
I was incorrect here.
A cubic meter of O2 weighs about 1.400.000 mg.
Air consists for about a fifth out of O2.
Renfro
Well-Known Member
Probably chucked it in the reservoir, you know to destabilize the pH lol. Pointless to use an air stone with flood and drain.
Keesje
Well-Known Member
"why' would have been my 2nd question 
But you are right indeed: Totally useless to have an airstone in another hydro-system like waterfall, ebb & flow, drain to waste.
The movement of the water is the reason that the water absorbs oxygen.
(The same with an airstone btw: It are not the tiny bubbles that bring the oxygen in the water. It is the movement of the surface once the bubbles get there)
But you are right indeed: Totally useless to have an airstone in another hydro-system like waterfall, ebb & flow, drain to waste.
The movement of the water is the reason that the water absorbs oxygen.
(The same with an airstone btw: It are not the tiny bubbles that bring the oxygen in the water. It is the movement of the surface once the bubbles get there)
Mechanicalbuds
Active Member
A deep vessel filled with rock gets no airflow at the bottom. When the 02 is used it can't be replaced until it is pushed out from the bottom. It does not matter what you call it. When flooding happens it brings new air with oxygen to the roots. You say that does not matter, I find otherwise.
Roots need to stay moist but the also need oxygen. When they use up the oxygen it needs replaced. Hints the term "used or old" air. That's why ebb and flow is better than most other forms of hydro, ino.
I'm not trying to argue, I feel you are hung up on a phrase confusing what was actually ment.
Keesje
Well-Known Member
We are not arguing.
We are talking about how we both think that things work.
I have some questions:
And if the O2 is used up, there must be some kind of vacuum there now, if new air can not come in?
Are the rocks so small that there are not even gaps of 2 mm, 1 mm or 0.5 mm?
If air can not reach those spots, how come water can get there?
I am really curious about your answers.
Because if what you say is true, how do roots in soil ever get oxygen?
Soil is far more dense then hydroton. The particles of soil are way smaller then any pebble of Hydroton.
So it is all packed together and still oxygen gets to the bottom of the pot. Even if it would be a pot of 20 gallons... oxygen will still reach the roots at the bottom. Except when you over-water of course.
We are talking about how we both think that things work.
I have some questions:
How come it can't be replaced?
And if the O2 is used up, there must be some kind of vacuum there now, if new air can not come in?
Are the rocks so small that there are not even gaps of 2 mm, 1 mm or 0.5 mm?
If air can not reach those spots, how come water can get there?
I am really curious about your answers.
Because if what you say is true, how do roots in soil ever get oxygen?
Soil is far more dense then hydroton. The particles of soil are way smaller then any pebble of Hydroton.
So it is all packed together and still oxygen gets to the bottom of the pot. Even if it would be a pot of 20 gallons... oxygen will still reach the roots at the bottom. Except when you over-water of course.
Mechanicalbuds
Active Member
Cool. Not arguing.
Your right, there is gaps in rock.
I don't think if the 02 is removed there will be any sort of vacuum to pull more 02 in.
My table had 1 gallon nursery pots for holding rock. When filled, and watered, and then let to sit for several weeks( like when I'm lazy and dont clean after harvest....) The bottoms are always still wet. Its about airflow. There is no breeze getting air in there. If air was moving at all it would be dry like the top 3 inches of rock. The top will always dry quicker right? Because is can escape easily. But the bottom, no. Its trapped.
There is gaps as you say, yes, but no air movement....
Does that help explain some?
Ps. I'm no science guy, I struggle like everyone else!
Your right, there is gaps in rock.
I don't think if the 02 is removed there will be any sort of vacuum to pull more 02 in.
My table had 1 gallon nursery pots for holding rock. When filled, and watered, and then let to sit for several weeks( like when I'm lazy and dont clean after harvest....) The bottoms are always still wet. Its about airflow. There is no breeze getting air in there. If air was moving at all it would be dry like the top 3 inches of rock. The top will always dry quicker right? Because is can escape easily. But the bottom, no. Its trapped.
There is gaps as you say, yes, but no air movement....
Does that help explain some?
Ps. I'm no science guy, I struggle like everyone else!
Keesje
Well-Known Member
True, there is not really an airflow (the same as in soil)
But that doesn't mean that O2 does not get there.
The molecules are so tiny, they can slip through the smallest gap.
Like in soil. Plants even grow in clay soil (would not suggest it for your grow though )
The benefit of Hydroton is that even more O2 can slip through then in almost any other medium.
That your bottom stays damp has probably more to do with the fact that the water can not evaporate very well there. Some airflow would help, true. But there is still plenty of O2 there. Not of course when the bottom of your pot is closed and there is a layer of water.
O2 will sneak through the smallest and tiniest holes.
Thank God for that, otherwise corpses in a graveyard would never decompose
But that doesn't mean that O2 does not get there.
The molecules are so tiny, they can slip through the smallest gap.
Like in soil. Plants even grow in clay soil (would not suggest it for your grow though
)The benefit of Hydroton is that even more O2 can slip through then in almost any other medium.
That your bottom stays damp has probably more to do with the fact that the water can not evaporate very well there. Some airflow would help, true. But there is still plenty of O2 there. Not of course when the bottom of your pot is closed and there is a layer of water.
O2 will sneak through the smallest and tiniest holes.
Thank God for that, otherwise corpses in a graveyard would never decompose
Keesje
Well-Known Member
So I guess you have buckets or something like that.
In each bucket hangs a netpot.
When the bucket fills up with water, also an airpump with an airstone begins to work.
Something like that?
JohnDee
Well-Known Member
Just wanted to mention...back when I first did hydro, E&F...there was a little fitting that came with my water lift pump. It was a 1/2" fitting with an air connection on the side. Not sure what it was for...I stuck it on the hose going up to the tray. Plugged airline into it...and plugged the air pump into the flood timer. So air got injected into the hose as the water rose up to the tray. Had the parts...why not. Never had any ph issues either.
JD
Keesje
Well-Known Member
Sounds like a venturi
JohnDee
Well-Known Member
Or some kind of snifter port...for anti-siphoning. Anyway...worked good.
JD
Keesje
Well-Known Member
Normally E&F must be more then enough to have maximum DO in your water.
So it is pointless to have an airstone or a venturi.
Also, one of the main benefits of E&F is that in 'Ebb' the roots are surrounded by O2 in gaseous state while they are still wet.
Only if the E&F system is not designed well or something else is wrong, airstones or venturis would perhaps give some benefit.
But I don't see which one that could be.
The easiest thing to reach in hydro is maximum DO.
Only in systems where the roots are in water 24/7 it can sometimes happen that the rootball is so dense, that the water inside this rootball does not change enough. Then an airstone underneath this rootball could help.
But with E&F the rootball is relatively dry now and then. So there is always enough O2.
So it is pointless to have an airstone or a venturi.
Also, one of the main benefits of E&F is that in 'Ebb' the roots are surrounded by O2 in gaseous state while they are still wet.
Only if the E&F system is not designed well or something else is wrong, airstones or venturis would perhaps give some benefit.
But I don't see which one that could be.
The easiest thing to reach in hydro is maximum DO.
Only in systems where the roots are in water 24/7 it can sometimes happen that the rootball is so dense, that the water inside this rootball does not change enough. Then an airstone underneath this rootball could help.
But with E&F the rootball is relatively dry now and then. So there is always enough O2.
PopeyeSpinach
Well-Known Member
Well I can tell you that having air stones in a reservoir for Ebb and flow makes th PH spike more. If you have them in the tray, Ive never done that. And it sounds kind of weird too
C@nn@b1@n
Active Member
I've run buckets with airstones for years, so when switching over to ebb and flow (initially I was running 4 on/off @ 15 min) I felt running it that long without air would drown them. I left it in (switched to 8 on/off @10 min) and the 2 that don't get air are nowhere near the same size.. The next run will have even more air than this one.
Keesje
Well-Known Member
I don't really get your ebb & flow schedule.
PopeyeSpinach
Well-Known Member
I think your flooding way to long, you should never need airstones and they should not make a difference. I dont think ive ever flooded for more than maybe 4 minutes every 4ish or more hours. Just long enough to flood the tray full and circulate the reservoir solution a bit.
Once a large root mass has grown, it will retain water for a while. Ive had days go by after harvest before i cleaned my flood trays out and they are still wet.
Once a large root mass has grown, it will retain water for a while. Ive had days go by after harvest before i cleaned my flood trays out and they are still wet.