how often should i flood

in a dwc, there is constant oxygen being pummped by air stones, in ebb and flow the table is being flooded, and if its being flooded too much for too long, roots do not get the proper oxygen and will suffer eventually from some kind of rot or overwatered looking plants , my point being watering in the dark can only beneifit your plants, even just to keep the roots from drying completly out or not getting enough oxygen, so for someone to say definitivly that it should not be watered in the dark is wrong

informative thread!

Roots respond well to some dry periods

I am always experimenting, currently growing with Hybrid DWC, and My DIY 21st Century F & D + HPA (high pressure aero). It has taken me 5 grows to get a handle on hpa, but the key is short bursts of nutrients under high pressure (~80-120 psi) with pauses (dry periods) in between; currently 2 seconds on & 4 minutes off. Roots never get too wet or too dry, and they love it.

Enlarge pic and note many thousands of tiny root hairs. These are super efficient at converting the nutes to energy



Taking a page from this, I have been developing my F & D method, which is readily expandable. I use lava rock + Air Pots. LR is fast draining but holds small amount of nutes between feed cycles

Feed time varies depending on maturity of roots in veg or flower.

The lowest on setting with my current timer is 23 seconds. They really don't need to be flooded ala typical F & D, so I use fewer mist heads per plant.

I use a cycle timer with analog o/o settings

I feed from the top using low pressure mist heads (see photo of early prototype- sans mist heads) screwed into pvc. Without mist heads it gets all Bellagio water show, which is too much for young plants, hence the switch to low pressure mist heads




Once plants have ~ 5+ nodes I increase feed cycles to every 20-30 minutes. During flower I cut back to 45-50 minutes.


Below, you have to look carefully for the pvc bars with mist heads

ebb/flo 3X w/lights on, Hytroton lucas 400w dwc Hytroton lucas 400w

Forgot to mention that I use 6" netpots suspended into a tray and no media roots just hang. So you guys are saying I could leave pump off for a few hours before flood? Would the roots not get dry?

I still dont get it lol so does it hurt to run 24/7 as I have been doing? TBH I dont want more growth lol they have taken over a 4x4x7h grow area and are comming out the door. The root balls are massive and white. , These plants are around 55 days old and as I said I have had pump on 30 min, off 30 min. I have been reluctant to turn off for longer for fear of drying roots. What are the advantages of a longer off time? And if they get bigger with more off time then I'll have to raise the shed roof!!! lol. Perhaps they wouldnt have stretched so much with more off cycle?

waterdawg said:

Forgot to mention that I use 6" netpots suspended into a tray and no media roots just hang. So you guys are saying I could leave pump off for a few hours before flood? Would the roots not get dry?

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"Some" dry period does not translate to a few hours.

Never too wet, never too dry is ideal (HPA), anything other than that is about balance. Not an option with DWC, but can be compensated via lots of air bubbles and less water/nutes

You have to feel how long it takes for hydroton to dry out 2" below the surface (depending on whether you blasting with 1K, or low radiant watt leds). That's the amount of dry time you've got to work with. Adjust timer from there. With my method, each 1G Air Pot gets ~ 4 ounces of nutes per cycle, but 90% drains out very quickly. In HPA ~ 98% drains out

waterdawg said:

I still dont get it lol so does it hurt to run 24/7 as I have been doing? TBH I dont want more growth lol they have taken over a 4x4x7h grow area and are comming out the door. The root balls are massive and white. View attachment 2413578, These plants are around 55 days old and as I said I have had pump on 30 min, off 30 min. I have been reluctant to turn off for longer for fear of drying roots. What are the advantages of a longer off time? And if they get bigger with more off time then I'll have to raise the shed roof!!! lol. Perhaps they wouldnt have stretched so much with more off cycle?

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Looking at the leaves near the bottom, they are almost round (to much water). You need a more adjustable timer (~$80) In the mean time, try 15 min on 30 min off

"Looking at the leaves near the bottom, they are almost round (to much water). You need a more adjustable timer (~$80) In the mean time, try 15 min on 30 min off"Well I may try a different time schedule on next grow but am almost ready to pull this one but my timer has 15 min increments so that shouldn't be issue. The clay balls are only about 3" deep in the pots so like maybe Ill watch the plants closely next time and see if they are drying out after like an hour of down time and Im sure that as the plant gets older the root balls will hold more moisture as the whole res is now one big matt about 6 " deep. And I thought the big leaves were the strain lol. opps! I am thinking I'll average an ounce a plant for my first hydro grow so very happy with results at 70 days start to finish.