passive plant killer

[Carl Carlson]

Cactus, I don't think you can't toast your plants using Osmocote Plus...

That's part in part the beauty of it. It is pretty much stoner proof.

 

[Carl Carlson]

D9, maybe amending the coir is the last thing you can do to get yields to go up?

In my last grow I used a few different media combinations and two plants grew in MetroMix 560 w/coir which contains a starter nutrient charge with Gypsum, dolomite lime and nitrogen.

Those plants grew taller and yielded more than the rest... For a while I thought about it and concluded it was the mix itself, but now I'm thinking it was the amendments.

So now I'm using the Oscomocote Plus along with the Peters hydro combination.

I'm also going to try a soilless mix with more amendments, d. lime, gypsum, blood, bone, kelp mix - together with the OC+ - watered with plain water only occasionally hitting it with Alaska 5-1-1 or molasses if need be - in order to see how this compares in terms of yield and quality against the Peters + Osmocote.

http://www.greenhousegrower.com/magazine/?storyid=248

Combination Fertilizer Programs
Combination fertilizer programs for flowering pot plants can be the best bet for consumer success.

By Fred Hulme
Contributing Author
May 2007

Plants with no fertilizer (either CRF or water soluble) performed very poorly (Table 1). The limited growth produced by these plants was likely achieved by using the starter nutrient charge in the growing mix. In general, as fertilizer concentration increased, plant growth (indicated as dry weight) also increased. The maximum dry weight measured was for plants grown at the highest concentration of CRF and 300 ppm N twice a week: 253.8 g, 220.8 g and 253.6 g for petunia ‘Easy Wave Pink,’ petunia ‘Wave Blue’ and verbena ‘Wildfire Rose,’ respectively.

[..]

As expected, plants with no fertilizer (either CRF or WSF) performed very poorly (Figures 1 and 2). In general, as fertilizer concentration increased, plant growth (indicated as dry weight) also increased. Although some dry weights for the 3.8 oz. per pot treatments were smaller than the ones for the 2.9 oz. per pot treatments, these differences were not statistically significant. Plants that received WSF at 600 ppm N once month with no CRF were lighter (smaller) than any of the plants that received CRF (Figure 2). Even the lowest CRF rate (2.9 oz. per pot) produced more biomass than the plants in the treatment imitating how an average homeowner might fertilize (600 ppm N once per month). Measurements for heights and diameters followed the same general trend as dry weights.

[..]

Recommendations
The Scotts Company recommends growers choose a WSF program based on a complete water test. The CRF component should provide a steady and extended release of N-P-K, Mg and minor elements. Match Osmocote Plus longevity with your growing temperatures and desired delivery time. In most cases, a CRF with eight to nine months longevity will perform through production to provide post-production feeding of flowering crops for the retailer and consumer. Please refer to the label for specifics.

Recommend rates:
■ Use the low CRF rate (around 3 to 4 lb/cubic yard) for salt-sensitive, tender species such as fuchsia, begonia, fern and impatiens; for bedding plants; high water-retentive media; minimal leaching.
■ Use the medium CRF rate (around 5 to 6 lb/cubic yard) for more vigorous species and heavy feeders such as trailing petunia; low water-retentive media (containing coarse bark); frequent leaching.
■ WSF concentrations need to be lowered when using in combination with CRF. Reduce your constant feed to 50 to 75 ppm N for bedding plants, 100-150 ppm N for flowering pot crops and baskets.​

 

[delta9nxs]

D9,

With regard to sump length: I was referring to length extended into the bucket specifically.

MY GOAL: I do not want to remix nutes and destabilize the solution with run off from the root zone.

1. If I'm pulsing with the right volume, this bottom 'catch' is irrelevant.
2. If the 'pure' top-pulsed solution is over-pulsed, and it's excess is captured in the bottom of the bucket, I achieve my goal. The capillary action should be sufficient to move it back up throughout the medium (and back down the sump if i really mess up on volumes).
3. In your perpetual cycle, it seems likely that the only plants being over watered are the youngest transplants to veg with the least established roots. That is, even if I'm wrong with point number 2, there roots haven't made it to the standing water (which, in my understanding of hydrodynamics, won't be there any way).

Best wishes...

hey,IF!

i think i understand you this time around. the only caution i have with this is that if you are pulsing enough to cause a bottom "catch" then you might be keeping the medium too moist and thereby decreasing air porosity. possibly growth rate.

any standing water in the root zone is to be avoided.

i feel that if you are watering properly you are really just watering the medium. keeping the air/water ratios almost perfectly correct 24/7. i am now watering mine right through the dark period as i like the top to stay at the same moisture level.

in this device it is the constant slow motion of water and nutrients that keeps the ph and tds in the medium almost perfect. no salt build up.

i may be misunderstanding you still. a drawing or photo would help me a lot.

later

 

[delta9nxs]

carl, thanks for this link. really interesting. a lot of info on that site.

it would be convenient to just hook up the ro line straight to the float valve and forget about it.

but even if you had to supplement with liquid feed for a bigger yield it would be worth it.

i'm very hesitant about using organic amendments in this thing. if you seal openings and use a water soluble program like peter's or jack's, the reservoirs stay really clean.

hey, what do i have to do to get you to try a pulse fed ppk? i'll build it for you and deliver it loaded with clones, give you a 4 month supply of ferts, and an unconditional lifetime guarantee.

all you have to do is sign this contract giving me perpetual rights to 25% of your yield.

and your soul for all eternity!

d9

 

[Carl Carlson]

this is what happens

or this

And I tried to build a PPK, but cut the wrong size holes for the pipe and screwed the whole thing up.

 

[ImaginaryFriend]

D9,

I think we agree.

The penetrating sump depth (height?) is a small detail that I believe cannot hurt.
It might help in isolating accidental run off from the root zone back into the res.
That might help with long term stability.

I follow your approach on the quantity of the pulse.
I squeeze a bit of moisture between my fingers, but do not get drips at the current settings.

As for the "catch zone": I had a little run off when I first transplanted, which I attribute to the fully saturated medium just being put into the pots. My pulses (even at the two ounce level) were enough to push fluid out of the system. I was thinking of pulsing more often when the transplants were new, but now that I see the moisture content in the coco, I don't think that'll be necessary.

My room is running super hot right now, and my res temps are around 100 (I'm pushing 1200W at the baby girls). They seem fine, four days into it. I just need to be patient and wait for the root mass to expand.

pH is stable.

All seems well so far.

Really liking this system. Based on your long term observations, I simply trust it.

I'm seeing a couple of experienced MPB operators considering transferring back to chow or DTW perlite setups (mrdizzle and a couple others over at the farm). The rDWC results are monstrous, but failures seem complete. I'd rather harvest 47 plants in a row (or whatever you're at now) with a bit less yield each (although I think I guessed at your two-month yields and they are not shabby at all. You're running 4K, right?) than loose an entire room. The numbers have to be huge (i.e. gaining 20%) over the PPK in time or yields, before you can recover one cycle (presuming one room) lost to a RDWC failure.

ONE LAST OBSERVATION: You are committed to the top pulse based upon plant response, regardless of the root moisture transfer you talked about pages ago.

 

[ImaginaryFriend]

Carl,

Delta's put out a pretty generous offer there...

 

[Carl Carlson]

at some point i will try with it again.

and yes D9 as far as amending the PPK, only the OC+ would seem to be applicable. You should try the CRF + WSF combo in that thing. Everyone should. The OC+ is really inexpensive. And everyone else that is currently growing with synthetics in hempy buckets or coir or peat in containers should try the OC+ too.

 

[ImaginaryFriend]

carl...

I follow your links all over the place, and the info in Doc's thread (and your contribution there) has me more than ready to try the CRF+WSF combo for sure. 'Course, there's a few days between now and then, but I definitely think I'll be loading up the next bucket with CRFs to see how she runs... maybe have a little N and K in the WSF top pulse...

With regard to amendments: I see a great opportunity to run a properly aerated organic pre-mix with this system, with the wick topped off with RO. I don't remember who did it, but someone on here used Blumats in a two shelf vertical tent... feeding just water into his organics and slayed it. Blumats should also keep the medium pretty evenly moist, but maybe the PPK has an edge on consistency in humidity.

On the PPKs:

My little garden is loving life right now, is stable as can be running my existing Botincare nutes at 4-1-5.5 (next mix should be a bit closer to 3-1-3 or 3-1-4 but I've gotta actually write out all the micros and do the math on that blend to see if I'm really ODing on anything).

I do plan on running Jacks/calnit as soon as I get my act together.

I'm running the initial res a bit hot (EC 2.4), pH 5.8, but my top off res is setting at EC 1.8, pH 5.8.

Too soon to really see anything in the way of deficiencies, etc, but I transplanted 5 days ago and have 4xvegetable volume. Pulsing the coco in PPKs seems to make these girls pretty happy.

 

[ImaginaryFriend]

Running res temps of 103 today. Have a $600 chiller on the shelf beside the top-off reservoir. It is not plugged in.

D9, am I being stupid?

I know I should start my own diary, but I want to give it a few more weeks. (Unless you say otherwise Delta.)

So here's to cluttering your thread, and answering my own question with: "Girls say, 'no'." First pic is a baby just after transplant... Second pic is six days later.







My photography skills can't really capture the change...

I did a little training yesterday to try and pull secondary growth down to inspire a more aggressive vertical lead. Today, all the side stuff is back up and bushy again. So much for that plan.

I am resisting the temptation to defoliate, 'cause I have way more light than canopy right now. I hope I can give it a week to do it's own thing...

Anyway... the only other detail is that my closet is running between 650-850ppm CO2 depending if I'm around or not... and I haven't bothered replacing the battery to my thermo/humidity monitor. But I bet it is scary as hell.

I think roots must be doing starting to do something... getting into the middle of the bucket? Who knows? I'm not pullin' them to find out.

Anyway, PPKs are holding up well to my environmental negligence. D9's work is fully legit up to day six in my hands...

 

[delta9nxs]

hey, everybody!

i've been tied up the last two days. all day yesterday trimming another big plant.

all day today at the hospital enjoying being poked, prodded, stuck with sharp shit, and starved. i couldn't eat or drink anything for 24 hours. just routine testing. got go again in a month.

they do give you some pretty good pain killers though.

last week's plant, the one immediately following the 18 zip one, weighed in at 15.80 dry.

the one i cut yesterday is at least as big. report next week.

this is getting interesting.


carl, damn you! now i'm reading all night long about the differences between controlled release, timed release, and slow release. also the different structures of the prills. moisture and/or temperature triggered release. research papers with references to the combination feed technique you were talking about. it all looks promising.

IF, thank you for the plant pics. your plants look great. i can't see any problems at all.

that 100* temp is scary. it would be interesting to see what the temp is in the center of the medium. i use an old digital meat thermometer. i bet the medium is not over 85*.

i gotta get some rest now but i'll try to come back tomorrow.

 

[krueger420]

wow nice plants.

 

[Carl Carlson]

D9, did you see this one?

http://www.springerlink.com/content/l724228h472tu350/

OC+ releases ammoniacal nitrogen first and foremost.

Multiple applications perhaps better than one big one.

 

[ImaginaryFriend]

Maybe that's why the pulse feeding of N @ 300ppm was found to be effective in blending the CRF and WSF combo... If the shell/membrane inherently releases amonia-nitrogen so quickly, maybe the added N dosing can make up for that depletion (or change the osmosis rates via saturation).

 

[delta9nxs]

hey, krueger420! welcome!

carl and IF, i just read a paper that dealt with the release rates of NH4 using different application techniques.

the two most popular methods of application are top dressing and incorporated. they found that NH4 depleted more rapidly using incorporation.

i don't like the idea of any ammonium or urea forms in my solution. i think it causes unnecessary stretching during veg and preflower and elongated, airy buds.

it also causes ph swings. down when initially mixed, then up as it is depleted.

i think nutricote makes an all nitrate version for the orchid crowd.

all these kinds of fertilizers are marked "type 100", "type 140", and so on. this refers to the length of time the product usually takes to release 80% of it's nitrogen.

so for me, with a 16 week time frame, type 100 would probably be best.

because of the way my system operates it would be very difficult for me to experiment with this. i would have to isolate one container with it's own feed.

 

[ImaginaryFriend]

D9,

Thanks for your input on that article (especially the nutricote nitrate note).

I don't think it would be too hard to isolate a cell to run it's own nutes/pulse... but maybe that's because I have shelves of equipment collecting dust. I'm game to try this relatively soon (i.e. over the next couple of months).

I'm not too worried about pH swings based on what I've read about the form of CRF's nutes...

I'm running Botanicare Tri-Flex, as I haven't gotten around to putting together an order for Jack's (I have checked out the website, but didn't go so far as to find the shopping cart). I think my nutes have both ammonium and urea forms of nitrogen... and I have the opposite of stretch right now... inter-node lengths are sub-5/8" and the plants are wider than they are tall. Could be light proximity, could be strain, could be training.

*EDIT: PH seems to be creeping up a bit.*

Temps are still mad out of control. Res temp numbers are through the roof (top off res 104). I guess I could run my chiller as a water based AC, but the plants canopy is are so thick and green right now... and every time I check on them, I see growth (over three to five hours). Maybe if I did a better job controlling temps I'd see an even more explosive growth. Who knows. I'm not in a perfect environmental control situation right now, and my ambient temps are pretty damn high to start with.

My leaves are atypically leathery, though. Any ideas that?

Still stoked on the PPK. Not scared of what I'll find when I say hi to the girls...

Best wishes.

 

[*mistress*]

ammonium nitrogen generally make ph decrease in media.
nitrate nitrogen make ph increase in media/solution....

The form in which N is absorbed has an effect on the media pH. As NH4is absorbed, the plant releases H+ ions to maintain electrical balance, and therefore, the pH drops. As NO3is absorbed, the pH increases due to presence of increased amounts of OH-ions. Uptake of N, therefore, can explain some of the fluctuations sometimes seen in the pH of the growth media.

 

[Carl Carlson]

FYI ya'll: Nitrogen: All Forms Are Not Equal

http://www.gmpromagazine.com/gm_0609_nitrogen.aspx

 

[knna]

ammonium nitrogen generally make ph increase in media.
nitrate nitrogen make ph decrease in media/solution....

"The form in which N is absorbed has an effect on the media pH. As NH4is absorbed, the plant releases H+ ions to maintain electrical balance, and therefore, the pH drops. As NO3is absorbed, the pH increases due to presence of increased amounts of OH-ions. Uptake of N, therefore, can explain some of the fluctuations sometimes seen in the pH of the growth media."

Are you saying it is the opposite that the quote?

Please, explain it a bit, Ive always seen NH rich fertilizers used to fight against high ph, I would be very suprised if actually is the opposite

 

[Carl Carlson]

Are you saying it is the opposite that the quote?

Please, explain it a bit, Ive always seen NH rich fertilizers used to fight against high ph, I would be very suprised if actually is the opposite

No, Knna, it's the other way around.

Fertilizers that contain a relatively high amount of Ammoniacal Nitrogen will tend to decrease medium pH over time.

This is why if you are forced (yikes) to use a water source that contains a relatively high amount of alkalinity (acid buffering capacity), it should be matched with a more acidic fertilizer that contains a relatively higher amount of A. Nitrogen.

The Peters / Jacks hydro that several of us are now using is formulated for use with RO water and contains NO A. Nitrogen whatsoever.


And to find out how the process works in organic soil with the food web, read this: https://www.icmag.com/ic/showthread.php?t=186848