Grow Mediums Ebb & flow height/ frequency?

[GeorgeCloney]

I've got 8 seedlings ( 2 weeks old) in 7.5 liter airpots.
The airpots are in my 2x4x5 ten.
The entire setup is complete with led lights fans etc

The 8 pots are sitting in the 2x4 tray which is about 6 inches high.

Now to the question/details.
The setup is with a 165gph pump.
Inlet to the table is 1/2 pipe and the return is 3/4 inch.
Both inlet and outlets are via botanicare fittings.
The return fitting is sitting about 4 inches high from the base.

The question now is.... How long do I flood.
Is 4 inches too high or too low
I forgot to mention timing is done through a digital timer with full control...so I can control both when flood happens( frequency) and how long ( duration).
Photos are available if required
Cheers,
GC

 

[Mañ'O'Green]

@GeorgeCloney are you doing a flood and drain to water some media from the bottom? I could use some pictures.

 

[Animatey]

Some info that would help:

What media is in the pots?

How tall are the pots?

 

[GeorgeCloney]

Coco/perlite top to bottom.
Hercules pots (7.5 liter).
Flood with return to the reservoir.
Photos to follow in the morning.
Thanks for the response @Mañ'O'Green

 

[Mañ'O'Green]

The easiest way to determine how long the Flood stage needs to last is to just fill one of your pots with your coco/perlite mix, Weigh it, place it in a tub of water at the depth you will have in the flood tray and time how long it takes the water to wick to the level you want. Weigh it. Now subtract the starting weight from the wet weight this is your water weight. Place the pot in the grow room under the grow conditions and time how long it takes for it to lose half of the water weight. This is the maximum time between watering when you start. This time will get shorter and shorter as the plants grow. Since you will not be flooding over the top of the medium you should plan on top watering to waste every 7 to 10 days. I have not done this in coco but I am extrapolating from a rock wool flood and drain that did that did not reach the top of the cubes. It developed a salt line build-up at the water level inside the media and eventually the plants died. This was a long time ago but a painful lesson. All I had to do was top water to rinse it out! Any how don't know if coco would behave like that?

It will take 20 gallons to flood to 4" deep plus enough reserve in the tank so the pump does not run dry. Experiment with different depths and soak times maybe 2" and a few more minutes will work as well?

 

[Death The Cultivator]

I'm in stonewool but I run 9 x 5 gallon pots in a 3x3. I flood to 25% of pot height but my media only needs it every 3 days. It takes about 5 minutes to flood then drain my tray.

You can check Vader OG, he has videos on how he does it in coco.

 

[GeorgeCloney]

@damien50 @Mañ'O'Green @pop22 @St. Tom @Olderfart

So I'm into my 5th day of ebb and flow.
Plants are looking decent.
They popped 9 days ago, so all things considered, I'm happy.

I'm flooding about 4 inches(10cm).
5 minutes of flooding every 3 hours.
Nute mix is 500ppm of MC.
PH @ 6.1

Leaves are a little on the pale side.
(Looks like N def'c.)

Btw, 4 inch flood is 30% of the pot.

Although this is farts and giggles.
The plants are doing well.
Opinions, comments?

 

[Mushinronsha]

@damien50 @Mañ'O'Green @pop22 @St. Tom @Olderfart

So I'm into my 5th day of ebb and flow.
Plants are looking decent.
They popped 9 days ago, so all things considered, I'm happy.

I'm flooding about 4 inches(10cm).
5 minutes of flooding every 3 hours.
Nute mix is 500ppm of MC.
PH @ 6.1

Leaves are a little on the pale side.
(Looks like N def'c.)

Btw, 4 inch flood is 30% of the pot.

Although this is farts and giggles.
The plants are doing well.
Opinions, comments?
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Ill take a stab at it since I feel like I am one of the few that use ebb and flow in the forums. I honestly do not know much of the environment you are growing in, but I will say I use Hyrdoton/ clay pebbles, which dry's out a lot quicker than coco. I only flood once ever 4 hours and skip the flood cycle while the lights are off. I flood to 1 inch from the place the seed started. So if my seed is an 1" down from the top, I flood 2" inches from the top. It fills, sits for like 30 secs and drains. I've been using this same cycle for like 2 years now and have never had an issue with under/ over watering. With that being said, I have been interested in trying to flood every 3 hours, just havn't pulled the trigger on it. If its not broke why try to fix it . Anyway, happy growing mate!

 

[Death The Cultivator]

@damien50 @Mañ'O'Green @pop22 @St. Tom @Olderfart

So I'm into my 5th day of ebb and flow.
Plants are looking decent.
They popped 9 days ago, so all things considered, I'm happy.

I'm flooding about 4 inches(10cm).
5 minutes of flooding every 3 hours.
Nute mix is 500ppm of MC.
PH @ 6.1

Leaves are a little on the pale side.
(Looks like N def'c.)

Btw, 4 inch flood is 30% of the pot.

Although this is farts and giggles.
The plants are doing well.
Opinions, comments?
View attachment 1231861
View attachment 1231862
View attachment 1231863

Looking fine to me. I wonder how it will be come flower.

 

[GeorgeCloney]

I'm too lazy to turn this into a grow diary.

But I will post updates/ progress and pics for all to learn as well.
After having done some research on the web.
This is by far a not so exact science.
Growing in any medium has some general rules.
Using nutes has some general rules.
PH, has some general rules.

Ebb and flow has general Guidelines.
Everything is more/less and in the grey zone.
I suspect we learn and grow with either failures or success pending our grow.

Here is my first observation.
After 5 days the res went up from 500ppm to 510 (feed/evaporation?).
PH increased from 5.9 to 6.1

I'm flying this one vfr.

We'll let the plants tell us what to do