High-pressure (aka "true") aeroponics - nutrient schedule?

PetFlora

PetFlora

Well-Known Member
BobS: Killer set up. Can't wait to see the girls. If this is a clone rig it's tits, but if you plan to grow to harvest your roots will clog the PVC when you don't need it most. During buds new roots develop from the base of the root (called pompoms) their function is to feed the bud sites. If you're not feeding them freely, you will be disappointed in your yield. hth What light are you dropping in there?


Atomizer: Yes sir, you are 100% correct. I said that mine are not a good example just now. FROM MY POST ABOVE: "You won't find these roots in any other aero/hydro system, and they are not the best. When the root chamber is totally dialed in, {edit} all those lateral root hairs will fill with fuzz that are called root hairs. The fuzz significantly increases the surface area, allowing for more nutes to be absorbed at each feeding."

I have experienced lateral root hairs develop once I got all my parameters dialed in (without an Accumulator). 2 days ago I added a DIY chiller as my root pod RH was hovering over 80% for 5 days, due to warm weather. The root hairs should be showing soon now that the environment is condusive.
 
A

Atomizer

Well-Known Member
PetFlora said:
During buds new roots develop from the base of the root (called pompoms) their function is to feed the bud sites.
Click to expand...
Root hairs grow from the get go, if you`re not seeing any then you`re not providing the conditions for them to grow. Root hairs don`t increase the root surface area, (or arrive in time to feed the budsites come to that) they are simply an efficient means for a plant to increase its roots effective capture area for the lowest resource cost and in the shortest time.
Simply put, a root covered in fine root hairs will cost the plant a lot less than growing a solid root of the same diameter. Only the tip of a root hair is active..not the full length.
A chiller won`t help if you are putting too much mist into the chamber, the fact your RH increased with warmer temperatures indicates excessive misting. If you track the chamber RH you may be surprised by what happens to it over a 24 hour period.
 
PetFlora

PetFlora

Well-Known Member
Atomizer: I disagree that I am 'overmisting', at least by so much as to be the cause of lack of root hair development, but what's new. My tote is a rubbermaid; the top is thin too. Under 400 watts HO T 5, at roughly 2 feet above the plant/ root interface, there is sufficient radient heat to penetrate into the root chamber. Now that I added my DIY pod chiller, RH is in the high 50s- low 60s, and I am still feeding <2 seconds/2:15 pause. Now, I may be able to increase the pause now that the RH is lowered. I just need to keep an eye on it. I have personal experience seeing root hairs develop once the root environment is condusive. Stay tuned.

I did not mean to imply that root hairs only develop at budding, however, new roots, called pompoms, do.
 
B

Bob Smith

Well-Known Member
PetFlora said:
BobS: Killer set up. Can't wait to see the girls. If this is a clone rig it's tits, but if you plan to grow to harvest your roots will clog the PVC when you don't need it most. During buds new roots develop from the base of the root (called pompoms) their function is to feed the bud sites. If you're not feeding them freely, you will be disappointed in your yield. hth What light are you dropping in there?
Click to expand...
I'm planning to grow to harvest; it's 4" PVC; this is an experiment and nothing more, so if it turns out that the roots do indeed fully block the columns (I wouldn't be surprised if they do, but I actually think they won't, and the roots will stay towards the front of the column where the plant is), I can either just up my misting times or go to a full on LP conversion.

Did this more out of efficiency in not having to use a 1/6HP pump 25% of the time and the (theoretical) ability to drain to waste than I did to have pretty roots............but I'm gonna do a tree grow in a few runs (4 plants, each in their own 45 gallon container) where I WILL nail down the pretty white roots :)

Lights are four 600s stacked vertically on top of each other in an 8' cooltube.
 
PetFlora

PetFlora

Well-Known Member
Atomizer said:
Those fall well short of true aero roots as they are way, way too wet.
If you hope to spread the word about hp aero, you need to gain better control over your mist and grow some proper aero roots :)
These were originally in compost and are in the process of converting to the aero structure. They are purposefully kept on the wet side to aid in the transition from soil to mist, you can just make out the excessive moisture on the root hairs.
Your root pic bears a similarity to the older soil root sections (smooth, discoloured and waxy looking), real hp aero roots look nothing like those.
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I made a similar comment on Wiki. But the photo was about 6 years ago, if not older. Like adding text, I imagine new photos can be inserted. You wanna give it a shot?


Also, yesterday I cleaned a clogged mist head and forgot to reopen the drain cock from my rez to pump. Plants went without food for a couple hours. The small one (with the bigger roots) was wilted, but the large one didn't wilt at all. So, I extended pause from 2:15 to 3:00, and will see how far I can pause. Is there a feed/pause ratio as a guide- 1 to 3, 1 to 4... 1-20... ?
 
PetFlora

PetFlora

Well-Known Member
Feed-Pause Update: After a lot of experimentation, this plant top cannot tolerate more than 2:20 pause with 2 second feed. My roots are not totally normal, but pretty close. The tap root made a right turn about 4 inches down so it looks like a pony tail.

A longer feed time is counter-productive as it only soaks the roots. It could be that I would need to reposition the mist heads up high (easy to do), though I have them aimed high and the atomized mist does fill the entire pod. I also tried 3 second feed to increase the amount of atomized mist but roots were soaking.

The plant looks very healthy. I have tons of lateral roots but cannot see root hairs. They may be there and I just need a large magnifying glass to see them. hth
 
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Bob Smith

Well-Known Member
PetFlora said:
Feed-Pause Update: After a lot of experimentation, this plant top cannot tolerate more than 2:20 pause with 2 second feed. My roots are not totally normal, but pretty close. The tap root made a right turn about 4 inches down so it looks like a pony tail.

A longer feed time is counter-productive as it only soaks the roots. It could be that I would need to reposition the mist heads up high (easy to do), though I have them aimed high and the atomized mist does fill the entire pod. I also tried 3 second feed to increase the amount of atomized mist but roots were soaking.

The plant looks very healthy. I have tons of lateral roots but cannot see root hairs. They may be there and I just need a large magnifying glass to see them. hth
Click to expand...
Not sure about other people's hairs (that just sounds weird), but I can pretty easily see my plant's root hairs with my naked eye (and my eyesight isn't all that great, either).
 
A

Atomizer

Well-Known Member
If you are not seeing root hairs, the most likely explanation is the droplet size is too large. Without the correct droplet size range the 2sec / 2m 20sec cycle will only be providing enough moisture to prevent wilting (survival mode).
Root hair production is in response to droplets suspended in the air after the misting pulse ends, a wet/dry cycle alone won`t have the same effect. As a rough guide to droplet size, if your chamber is 18" deep and your mist clears inside 6 seconds the majority of the droplets are larger than 50micron. If it clears inside 3 seconds they are over 80 microns and inside 2 seconds.. you`re over 100microns.
 
PetFlora

PetFlora

Well-Known Member
Thanks A. It's perplexing. All leafs are fully extended reaching for the lights, as they do when I ff with S/LL, but haven't done that in weeks now that they are pistil packing. All leaves reaching for the sky is a whole new experience for me. sure seems the plant is loving what's going on below.

Differences from last grow where I had roothairs: I am using all DM Gold nutes. Only started adding DM Zone ~ 4 weeks ago. Also, until 2 weeks ago I was not adding FulPwr from BioAg, as I did throughout last grow. I just increased pause to 2:25 as the roots have large droplets hanging on them.

I am using the same pump, fog/mist heads as last grow. Is it likely that the mist heads have enlarged?
 
A

Atomizer

Well-Known Member
Not very likely unless you`ve noticed a difference in the amount of run off. The pressure from the pump may have changed.. might be worth checking.
 
PetFlora

PetFlora

Well-Known Member
I haven't timed it yet, but that's an excellent suggestion.

Late yesterday I increased pause to 2:25. Leafs still reaching for the sky this morning, so will shoot for 2:30.

Hopefully I will find the point where plant is fine and root hairs develop before harvest. lol
 
PetFlora

PetFlora

Well-Known Member
2 days ago I increased pause- now at 2:30; all leafs still reaching for the sky, pistils growing nicely even seeing some trics. This with < 2 second feed cycle. However, after the following observation, and noting that at ~ 2 second feed the chamber cleared in less than 3 seconds, I increased feed to 4 seconds (pod clears in ~ 7 seconds) and pause to 3 minutes. I will monitor the pause over the next day (only one more hour of light left today) to see how long I can extend it, and whether this will bring the root hairs. Seems the feed/pause parameters are longer when not using an accumulator.

I also have a second crop going (4th week of veg). The first 3 weeks I was using a walmart twin stone bubbler. (I will replace this with an Elite 802 air pump and 2 Sunleaves 4" cylinder stones for future start -ups: it rocks some serious bubbles in my main system rez (I was using the walmart set up there). A week ago I moved these plants to a 18G pod using another Aquatec 8800. Two days ago I began adding flower nutes to the veg nutes. Feed time is being controlled by a DNe timer, whose lowest actual setting is roughly 30 seconds; I am pausing at ~20 minutes. The plants and roots are growing bigger and faster than I have ever seen. Lots of fishbones, but of course the roots are holding a lot of water droplets. I just repositioned the mist heads to see if that will minimize the problem. Seems like the veg stage is a lot more forgiving, or, do the roots simply need longer feed times during early veg?
 
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Bob Smith

Well-Known Member
My DNe timer goes down a helluva lot lower than 30 seconds (probably about 2 or 3, if I had to guess) - you sure yours doesn't go any lower? That doesn't sound right to me.

And how does your chamber clear in three seconds? Do you have an extraction fan hooked up to it? My chamber(s) are obviously a lot smaller, but that mist hangs around for a while (never timed it, but at least 30 seconds and probably closer to a minute) - also, my mist times are longer than desired to make sure all plants receive enough water until their roots are large enough, so that may have something to do with it.
 
PetFlora

PetFlora

Well-Known Member
BobS:

I was thinking to contact the DNe mfg to ask that very question. {ed. Turns out it's an IGC- they look alike.} Wonder why I never did. No extraction fan per se. I do have an oscillating fan aiming above horizontal to fluff the leaves. I doubt it had an effect.

Mist: In 18G with < 2 seconds using 2 @ .9gph heads, I observed my 18G pod clearing that fast. At 4 seconds more like 7-8 seconds. I am now focusing on how long I can pause; just increased from 3 min to 3:15.

Revelation?: What I may be closing in on (finally), is that without an accumulator the feed cycle needs to increase dramatically. I was always trying to keep the accum feed cycle (~ <1 sec), thinking it was an important parameter. After observing the explosive growth from my new plants, I deduced that I needed to increase feed/pause times. While I was writing that up to post, a guy sent me a pic of his roots using something like 4 seconds and long pause (he wasn't exact) he had root hairs. This confirmed that I was finally on the right track.

Taken this morning. Note how all leafs reach toward the light. I must be doing something right, even if it isn't HPA, which I admit it isn't. I will revised my journal to back to TAG 2.0
IMG_0764.jpg

hth
 
A

Atomizer

Well-Known Member
I keep saying it ..the limitations of the pump is the problem :)
You need the longer misting duration to generate the pressure that delivers the right droplet size. The accumulator needs no run-up so it can use a shorter misting duration and delivers less water.
The longer pump duration gives you the peak pressure at the cost of delivering more water. You`ve traded one thing for another that requires you to use a longer pause to offset the excess water. With the well defined wet/dry cycle the roots wont feed constantly, they`ll just be waiting to dry out between mistings. Another step or two in this direction and you`ll have mist driven flood and drain. ;)
 
PetFlora

PetFlora

Well-Known Member
Yes, but.... equating my set up to F & D is not such a bad thing. In fact my first ever attempt to grow (30+ years ago) was F&D and I grew some serious trees. Of course the roots were in gravel and the feed cycles were much longer in between (something like 4xs a day), but it sure worked. If I can get similar results, I will be very happy.

At the end of the day is it not the root hairs that separate the men from the boys so to speak? It seems this is where the plant becomes the most efficient, but root hairs require a tightly controlled environment (including RH I would imagine) in order to develop. Clearly accums do this, but a grower asking a ton of questions on my journal using similar set up and times as I am now showed a pic of his root hairs.

FYI As of yesterday, I am now up to 3:25 second pause. The roots remain moist near the end of the pause cycle- impatiently waiting for root hairs.

Still waiting on someone who has an accum dialed in to show me pics of mid flower plant and roots to show why I should bite the bullet.

Taken this morning. Note how all leafs reach toward the light. I must be doing something right, even if it isn't HPA, which I admit it isn't. I will revise my journal to back to TAG 2.0


hth
 
PetFlora

PetFlora

Well-Known Member
Thanks BobS. Sweet. Not convinced that the result is >20% better than what I think I can do (his plants are much bigger genetics), but sweet nonetheless.
 
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