Anybody running a mediumless ebb n flow?
- Thread starter richyrich
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If anybody is running this type of setup, please, share your flood frequencies and any tips you may have.
With NFT, side by side experiments proved constant water gave more yield than 15 on/15off, I would cycle that system constantly myself, but why not just tip it up with a 5%+ slope and do NFT...
Nutriculture make excellent kits [E&F as well as NFT] that a massive proportion of UK growers use.
Medium can offer good support for plants, with no medium, you really need to think more about securing your plants with nets or similar, they never like falling over.
Thanks for the reply. NFT is exactly what I was thinking but I have the same trays as in the picture. The problem is that the holes are in the middle of the tray. There is no way to tip them for NFT. I am currently flooding for 6 minutes every 20 minutes with a recycle timer.
This type of set up produces big root mats that support the plants.
If you flood to infrequent then roots dry out. If you flood to often then the roots never get to dry out completely to get oxygen. The in between is what I am trying to figure out. I started thinking along the lines of NFT. How could I try to duplicate it by ebb n flow?
By flooding every 20 minutes, the roots will never dry out. The roots never get to completely dry out and some water sits in the tray channels. This is what has me worried. By flooding so often should I worry about the roots suffocating in the pooled water in the channels. My guess is that I shouldn't because it's not stagnant water since it is being replaced every 20 minutes. Should I worry that the roots are not getting oxygen by not letting them dry out a little. Thoughts?
This type of set up produces big root mats that support the plants.
If you flood to infrequent then roots dry out. If you flood to often then the roots never get to dry out completely to get oxygen. The in between is what I am trying to figure out. I started thinking along the lines of NFT. How could I try to duplicate it by ebb n flow?
By flooding every 20 minutes, the roots will never dry out. The roots never get to completely dry out and some water sits in the tray channels. This is what has me worried. By flooding so often should I worry about the roots suffocating in the pooled water in the channels. My guess is that I shouldn't because it's not stagnant water since it is being replaced every 20 minutes. Should I worry that the roots are not getting oxygen by not letting them dry out a little. Thoughts?
I tried the 15 on/15 off cycle after seeing it talked about in a commercial Greenhouse magaine, [the best place to learn proper shit imo] saying it offered better O2 uptake ... so tried it... it gave less yield than constant flow... so I would set up your E&F for a constant cycle.. a mate is developing an improved DWC system that involves raising and lowering the water, not just bubbling it.
Roots develop to suit their environment, including watering schedules.
It looks like you were right Chaos. After some experimenting with 4 min on 15 min off things are getting better. I went this way because I figured it would be some what like NFT in a flood n drain setup. Very frequent floods of nutes and fresh oxygen. What was very important that I did was lower the overflow so the tray barely fill by about an inch high. Full flood is not needed.
I believe if you were to run that setup continuous like chaos is suggesting, with the overflow standpipe set to a low flood height like you did...
You'll end up with in essence a DWC system, where the fall-back to the reservoir is keeping the solution highly aerated. but...
The only possible drawback being that the pump(s) may run much warmer and cause the solution to run too warm.
That being said, I think you're on the right track running on/off cycles which will keep the pump heat in check.
btw...who makes those e&f tray 'plug holding' tray toppers ?
You'll end up with in essence a DWC system, where the fall-back to the reservoir is keeping the solution highly aerated. but...
The only possible drawback being that the pump(s) may run much warmer and cause the solution to run too warm.
That being said, I think you're on the right track running on/off cycles which will keep the pump heat in check.
btw...who makes those e&f tray 'plug holding' tray toppers ?
O
ogatec
very interesting theory! i am a die hard ebb & flow fan but i might try "nft"ing 1 of my tables just to see what happens. i would think that the constant flwing of the watter under the lights would also contribute to heat gain in the rez. i guess covering the table would go along way in helping keeping the h20 cool..
