First Ebb & Flow

I'm setting up my first E&F system. I will be using a 600w HPS bulb in a aircooled hood. A 4x4 flood table will be used. I will grow in SOG.

1. How big (or small) should the netpots be?

2. How far up on the flood table should the water level go? I'll be cloning in to Grodan plugs and then use hydroton in the netpot.

3. I've been trying to find solid info on how often to feed them but there doesn't seem to be a concensus on it. Should I go with 3-4 times per light cycle?

Been growing in hempy buckets before but this is my first E&F, would like to get it right from the start.

Thanks

In Toronto six, six minute F&D's every 24 hours does a good job. It changes depending on where you are growing...like boiling an egg.

bird mcbride said:

In Toronto six, six minute F&D's every 24 hours does a good job. It changes depending on where you are growing...like boiling an egg.

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Thanks! Do you feed anything during the dark hours?

I flood hydroton every 4 hours when lights are on, no floods when lights are off. Flood long enough to reach full depth only. Plant the rockwool high in the pot so the roots get water but the rockwool doesn't stay wet.

The deeper the flood, the more space in the pot for roots, shallow flood, shallow roots.

Lazyeye1 said:

Thanks! Do you feed anything during the dark hours?

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I feed on every watering. I mix the NPK 1/6 per gallon as per outside soil instructions. Swap the res weekly.

Mine don't look good unless I flood every 15 minutes, 24 hours a day. I also experiment with root mat flood and drain. No rock, no rock wool, no nothing. Just a good fitting lid

My other runs have been flooded every 2 hours, 24 hours a day. With hydrotron filled 1 gallon buckets. I belive flooding is doing more than wetting roots. It is expelling old air and bringing fresh 02 to the roots. And that is most important

Mechanicalbuds said:

Mine don't look good unless I flood every 15 minutes, 24 hours a day. I also experiment with root mat flood and drain. No rock, no rock wool, no nothing. Just a good fitting lid

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I also flood 24 hours a day, every 30 minutes.

I flood for 10 minutes, it takes 8 minutes to fill my grow beds and takes about 2 minutes before my siphon kicks in to start draining the beds. It then takes about 5 minutes for the beds to totally drain and then I have a 15 minute dry period before I start my next flood cycle.

Over the years I've experimented with less daily waterings, but found the hydroton getting too dry between cycles for my liking. Some strains were fine with it, but others struggled. Since I run multiple strains on the same reservoir this RDWC/E&F hybrid works well for me.

Renfro said:

I flood hydroton every 4 hours when lights are on, no floods when lights are off. Flood long enough to reach full depth only. Plant the rockwool high in the pot so the roots get water but the rockwool doesn't stay wet.

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Great advice and basically how I ran my ebb and flow for 10 years.

Thundercat said:

Great advice and basically how I ran my ebb and flow for 10 years.

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Yeah I was running that for a long ass time myself and spreading that knowledge back around 2000 - 2004 on overgrow.

Lazyeye...I did a 3x3 tray E&F for quite a fw years. 4 floodings daily during lights on worked good for me. I put plants in small square pots. Could fit 23 in my tray. I liked being able to move plants around as needed.

Mechanicalbuds said:

My other runs have been flooded every 2 hours, 24 hours a day. With hydrotron filled 1 gallon buckets. I belive flooding is doing more than wetting roots. It is expelling old air and bringing fresh 02 to the roots. And that is most important

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When growing in hydroton...they get plenty of oxygen. I think you are applying a coco theory here...wrongly. No need to flood that often.

Cheers,
JD

JohnDee said:

When growing in hydroton...they get plenty of oxygen. I think you are applying a coco theory here...wrongly. No need to flood that often.

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I hear this quite often from other E&F growers -- yet they are consistently amazed at the trees I grow. Please remember that there are many ways to grow and just because it's different, doesn't mean it's wrong.

SuperiorBuds said:

I hear this quite often from other E&F growers -- yet they are consistently amazed at the trees I grow. Please remember that there are many ways to grow and just because it's different, doesn't mean it's wrong.

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I commented on your post because I didn't think it was good advice for a first time E&F grower. Just like the guy who commented that he floods every 15 minutes around the clock. Not pertinent (or logical)
JD

Mechanicalbuds said:

My other runs have been flooded every 2 hours, 24 hours a day. With hydrotron filled 1 gallon buckets. I belive flooding is doing more than wetting roots. It is expelling old air and bringing fresh 02 to the roots. And that is most important

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I don't get this.
What is 'old air'?

The sole purpose of flooding is getting water & nutrients to the roots.
When there is no water, there is air.
Air contains a lot of gasses of which O2 is important for the roots.
So what would 'old air' be?
Air without O2?
This could only happen if the air would be in a 100% sealed container and the roots would have absorbed all the O2.
If the container is not sealed (and this is the case with hydroton) new O2 will automatically flow in the container.

Lazyeye1 said:

1. How big (or small) should the netpots be?

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Depends also on how many plants you will grow in SOG style. Any idea yet?

Lazyeye1 said:

2. How far up on the flood table should the water level go? I'll be cloning in to Grodan plugs and then use hydroton in the netpot.

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As high as possible, but don't get the Grodan plug wet. So 2 cm or an inch below the grodan plug.

Lazyeye1 said:

3. I've been trying to find solid info on how often to feed them but there doesn't seem to be a concensus on it. Should I go with 3-4 times per light cycle?

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There was a test, done by a researcher from the world's best Agricultural University (Wageningen in the Netherlands) and she claims that the more cycles one does, the higher the yield. I am trying to find this paper, but so far no luck.
It makes sense: The plant has water+nutrient available at the moment it needs it (like in soil and DWC for example)
With Hydroton there will remain a film of water+nutrients in between the clay pebbles after it floods away, but after an hour it is all gone.
And what would be the benefit to only flood once every 4 hours for example? (except for electricity and maybe some heating up of the water because of your pump)

Keesje said:

I don't get this.
What is 'old air'?

The sole purpose of flooding is getting water & nutrients to the roots.
When there is no water, there is air.
Air contains a lot of gasses of which O2 is important for the roots.
So what would 'old air' be?
Air without O2?
This could only happen if the air would be in a 100% sealed container and the roots would have absorbed all the O2.
If the container is not sealed (and this is the case with hydroton) new O2 will automatically flow in the container.

Click to expand...

"Old air" to me is air in the root area that has used the 02 and requires expelling. Then the fresh air in is loaded with 02

Keesje said:

I don't get this.
What is 'old air'?

The sole purpose of flooding is getting water & nutrients to the roots.
When there is no water, there is air.
Air contains a lot of gasses of which O2 is important for the roots.
So what would 'old air' be?
Air without O2?
This could only happen if the air would be in a 100% sealed container and the roots would have absorbed all the O2.
If the container is not sealed (and this is the case with hydroton) new O2 will automatically flow in the container.

Click to expand...

If you think that it doesn't need flooded that often, that's fine. I was giving my opinion on different systems. My hydroton would be dry if it was not flooded that often. Yours might not be

Was flooding every 3 hrs day (4 times) and once mid night for 15 min per (with air stones under each pot) in hydroton; changed it to 10 min every 2 hrs with no flood during the night and they are loving it. Interested to learn if more people flood more often than that.

Mechanicalbuds said:

"Old air" to me is air in the root area that has used the 02 and requires expelling. Then the fresh air in is loaded with 02

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'Old air' does not exist in reality.
We sometimes talk about 'old air' in a room, where we ask people to open the window to get in some fresh air.
But that has nothing to do with lack of oxygen. It has to do with the fact that the amount of CO2 gets above a certain point.
It makes us feel not well, tired.

Using up all the oxygen could only happen in a 100% sealed box or something like that.
In hydroton however there are gaps where air can slip through. So fresh O2 will always slip through the gaps once the roots absorbed it.
So the air can not get old > The O2 can not get used up. It is a physical impossibility.
It is like 'communicating vessels'. Gasses will get evened out. (perhaps I am using the wrong words)
Imagine having two sealed rooms and in room A a candle will use up some O2.
The moment there is a small opening between room A and room B O2 will stream from room B to room A to even out the amount of O2.
The moment you open a window in either of these rooms, the amount of O2 will be at the same level in room A and B and outdoors.
The same with hydroton: The amount of O2 will be the same in between the pebbles and outside of the netpot.
O2 that is absorbed by the roots, will be filled up by new O2 in a second.

Of course in extreme circumstances, O2 can not move fast enough. But then we are talking about the the bombing of Dresden or something like that.
But we are talking about roots that use about 200 mg of O2 per kilo of roots per hour.
A cubic meter of air holds about 1,400,000 mg of O2.

Mechanicalbuds said:

If you think that it doesn't need flooded that often, that's fine. I was giving my opinion on different systems. My hydroton would be dry if it was not flooded that often. Yours might not be

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I am saying nowhere that hydroton doesn't need to be flooded often (or less often)
Getting in water+nutrients is a very good reason to flood. In my opinion more times flooding is also better. (based on some tests that I saw, and my thought that in that way the roots have more opportunities to 'drink'.)
So for reasons of getting in water+nutrients.
Not fresh air/O2. For that reason it is useless.