Calculating Nutrient profiles for Canna, GH and PBP

[Neptune]

Lucas, if you are around,

or someone with an answer...

I am wondering what a Lucas Formula should like like when growing in 6" rockwool blocks, Sea of Green, Ebb&Flow.. Right now I am using the basic GH Lucas Formula:

0-8-16, for 70 gallon res(with 60 gallons of water).. and cut back a tiny bit... week 2 bloom. 0ml-400ml-800ml = 5.6PH 950ppm (60 gallons of 30ppm tap water).

I have also decided to use some additives, Floralicious Plus at .75ml/gallon and Diamond Nectar 5ml/gallon. Thinking of adding Floralicious Bloom into this mix also, Seakelp is good shit. I would know.


basically, I am wondering what a good forumla using GH products would be for rockwool slabs, high density packing of 6" blocks.

 

[Lucas]

Basic medium based irrigation concepts:

Plant roots need to breathe between irrigations
The medium should not remain wet constantly. It is best if the irrigant is consumed within a 24 hour cycle
A pot of wet medium will cause numerous misdiagnosed nutrient overdoses and deficiencies, when what is actually happening is the roots are dying from lack of oxygen

let the medium breathe

irrigation frequency for a large pot with a small plant is totally different than for a large plant in a small pot

its all about not letting the medium get waterlogged for more than 24 hours

> What should the EC/ppm be of the nute mix when using a fertless soil?
> I'd like to feed with every watering.

high meduser
great to see your commitment to learning how to use the spreadsheet, excellent job!

The target EC of the root zone of cannabis is 2.0, how you provide that depends on how fast the medium dries out, how big the plants are, etc

I think irrigating with 1/3 of target EC in every irrigation is likely to produce a runoff of EC 2.0

bottom line is to confirm the EC of the initial runoff

> I am wondering what a good forumla using GH products would be for rockwool slabs

the same target EC of 2.0 in the root zone applies

again, you should measure the runoff to confirm how strong the nutes are in the root zone

as far as additives, I dont use any, so cannot recommend them

imho, additives are a way for folks to reinvent a nutrient program for cannabis

nutrients are not the determinant of yield or plant health, but you can certainly screw things up royally by messing around with multiple products

I recommend you use pH's spreadsheet to figure out what your custom mix contains, the way meduser did

Lucas

 

[Ausie downunder]

i use canna aqua and have found by week 4 of the clones that there is a magnesium deficiency i just spray with a 2% solution
Would i be better running it in the tank thru out the veg cycle

 

[senseless]

first off, thanks Lucas for all the work you put in to this thread contributing to us growers. it really helped me out.

currently durring flowering ive been using pbp at 15ml gal along with cal-mag as an additive. day 21 i started adding BioNova P13-K14. would this give me a good npk ratio through the rest of flowering?

thanks.

 

[Neptune]

Lucas is a firm believer in less is more when it comes to nutrients and additives. The basic principles apllied would suggest that you should keep the EC of the root zone at 2.0 (1000ppm @ .5 conversion) throughout the flowering cycle. Lucas would say, as he has said, that if you are trying to find a silver bullet for yield, that silver bullet is more light. If considering investin in fancy nutrients, then consider investing in more light and/or higher plant counts for larger yields.


how'd I do master Lucas? lol

 

[Ausie downunder]

lucas i have downloaded ph's spreadsheet
since i am currently using canna aqua flores i put those numbers into the spread sheet
the guaranteed analysis of part a was nitrate 3% k2o 6% Ca 2% Fe 0.04% chelated iron 0.04% part b was p2o5 3% k2o 5% Mg 1% s 1% b 0.01% Cu 0.002% Mn 0.02% Mo 0.002% Zn 0.009%
at 1.1 grams per ml the numbers for 3ml per litre came out as
n=99 p=43 k=302 Mg=33 earlier in this thread your numbers were
n=138 p=60 k=316 Mg=42 can you tell me why the numbers are different????
the grow numbers are different also

Does the lucas formula using Gh flora nova bloom 8ml n=124 p=108 k=180 Mg=62
(With targets of 100-100-200-60 with a run off ec of 2.0) apply to NFT channels with a constant feed????
If not what would you recommend ????

 

[Lucas]

> there is a magnesium deficiency

how are you diagnosing that? leaf spots (yes, thats Mg deficiency imho), or just loss of green between the veins?
Ive heard of that before with Canna Aqua, and they advise adding epsom salts. foliar is an excellent way to inject nutes into a plant.

> n=99 p=43 k=302 Mg=33 earlier in this thread your numbers were
n=138 p=60 k=316 Mg=42 can you tell me why the numbers are different????

the spreasheet has an option to check the "use weights" box. if you enter a weight, even if its just a guess, like copying the weight of Flora Bloom, the numbers come out stronger. this is especially true for thick nutes, like FloraNova

congrats on your spreadsheet work

> Does the lucas formula using Gh flora nova bloom 8ml n=124 p=108 k=180 Mg=62

yes, if you have entered the weight of FNB as 1.4666 and you check the box to use weights

> (With targets of 100-100-200-60 with a run off ec of 2.0) apply to NFT channels with a constant feed????

yes!
excellent question
the Mel Frank nute levels were tested for both ebb flow and bubblers, and I consider biobuckets and nft similar, because they all essentially bathe the roots in nutes either constantly, or constantly flushing with fresh nutes.

for high density medium, like coco, or synthetic soil mixes like sunshine, or even potting soil, I recommend an entirely different strategy.. which is to irrigate with 1/3 strength of Mel Frank's levels. The reasoning is that the nutes dont flush through the medium entirely, and instead accumulate over time..

irrigation of medium is an excercise in controlling accumulations, which is where flushing comes in. I dont think flushing applies to dwc, ebb flow, nft, or biobuckets..

and btw, check out my signature link Against Bubblers, for more interesting tangents on biobuckets..


> (using PBPB@15 plus Cal Mag@5ml/gal) started adding BioNova P13-K14.

why fix it if it aint broke?

> would this give me a good npk ratio through the rest of flowering?

no.

your PBP recipe is already fully functional. Adding more P will lock out Mg, which PBP has precious little of. Adding K is not necessary either, PBP Bloom is higher in K than GH Bloom products.

the people I know that add PK 13-14 are having endless loops with pH issues, nute overdoses, and in general, everything you dont want.

the only way I recommend using PK 13-14 is if you follow a manufacturer's guidelines for the rest of their nutes program. That is a Canna strategy.

mixing and matching nutes brands and products will have you flying blind in no time, unless you learn to input all your nutes into pH's spreadsheet, then learn the baseline target values for nutes, by studying the recipes I opened this thread with.

I recommend choosing ONE of the recipes I posted, they all work.

bottom line insight for me is, plants dont EAT, so feeding them more food is a bad thing. I think plants use the minerals in nutrients as electrical conductors. In the same vein, since plants dont eat, they also dont produce waste products the way we normally think of eating food and excreteing waste.

http://www.madsci.org/posts/archives/feb2002/1013824497.Bt.r.html
Autotrophic plants use light energy to make all the organic compounds they
require from carbon dioxide, water, and about 14 mineral nutrients they absorb
from their environment. Therefore, they don't really produce metabolic wastes

bottom line is its more important to control for the gasses, than the minerals. Oxygen is absolutely vital to roots, and carbon dioxide is absolutely vital to leaves. Therefore, airflow, air temp, co2 delivery, oxygenating the root zone, and lighting, are all more significant variables on yield than nutrients.

my advice is to pick a successful gardening mentor, copy their nutes, or pick a manufacturer, and follow their nutes program. then set aside nutrient concerns and focus on optimizing the environment.

hth
Lucas

 

[meduser180056]

Great advice Lucas.

With your info I've finally been able to aside my nutrient concerns.

I may switch to the PBPB hydro formula, but for now I'm using the soil formula and I'm in sunshine mix. It's cool how you can just use the bloom formula in veg too. Makes for less bottles. I've been using 15pbpb, 10cal-mag, 10 LK. They are the healthiest I've ever seen em. I've been testing run-off and keeping EC between 1.6 and 2.0.
PH of runoff has been around 6.0-6.2. I Ph the nutes to 6.2.

With small clones in 16 oz cups first watering was .8 EC. Then I upped it to 1.4 EC next watering. Next time I think I'll up it to 1.8-2.0 if they look like they can handle it.

With medium size vegging plants I've been watering with 1.8-2.0 EC every other watering and that's been keeping the run-off right around 1.8. They seem to like this schedule. I was surprised when I watered them with 0 EC water that the runoff was 1.8. I guess that's what they mean by nutes accumulating in the medium.

So not to contradict your idea of 1/3 strength every watering, but I've been finding full strength every other watering works better for me. I could see big plants doing well with 2 full strength feedings and then just water, but I haven't tested it yet. I'm loving this Sunshine mix. So much easier IMO than using soil with ferts already in it.

 

[all_is_1]

Phenomenal thread by a true professional. Thanks.

I've been considering running a drip system using coco/perlite/diatomite in ebb and flow trays. I'm wondering whether you guys (if jinxie is around I KNOW he'll have an opinion on this. . . oh how I mourn for the resources lost on overgrow. . . ) think that PB Pro hydro or soil formula would work better using a coco-based medium? Botanicare states that the reason that PB soil has more P and K is because the micro-organisms present in the soil use up P and K. This, while not contradictory to earlier things that I've read, is not something that I've read is an issue in any other source. If the microfauna are fed sugars my understanding is that they won't usie the NPK in the medium. Also, even though Coco-substrates are notorious for being nutrionally specific, my friend says he has had great success using coco slabs with PBP. Unfortunetly, he is, let me say, "unavailable" at the moment so I can't ask him more specific questions regarding his nutrient profile. Anyways thanks for the great info. Peace

 

[Guest]

If you replaced your reservoir every day with fresh nutes, (obviously very wasteful, but bear with me...) how much of a boost in growth would you get? What's the optimal number of days before changing the reservoir?

 

[aeric]

What's the optimal number of days before changing the reservoir?

GH website recommends 50% addback, then change. I recall Lucas once said at 75% he noticed a lag in growth. The common advice is to replace at 100%. I like somewhere between 50-75 in practice.

 

[mace_ecam]

If you replaced your reservoir every day with fresh nutes, (obviously very wasteful, but bear with me...) how much of a boost in growth would you get?

In DWC you would burn your plants with too much Nitrogen, its the fastest nute to leave the solution and go straight to the leafes, usually a matter of hours, sometimes 1-2 days, depending on res size.
More nutes do not produce more yield only burned plants.

 

[The Dopest]

i have an auto-topping R.O. filtered reserve. i use the GH 3 part but in the 2pt Lucas Formula (thanks Lucas) and have no way of knowing when the 50-75% mark would be. can someone put a general number of days on this or how should i go about renewing my system? its only about 10 gals total that recirculates through a small dwc setup.

thanks guys this thread is FULL of usefull info!

 

[Guest]

GH website recommends 50% addback, then change. I recall Lucas once said at 75% he noticed a lag in growth. The common advice is to replace at 100%. I like somewhere between 50-75 in practice.

I'm not sure what you mean by this.

 

[aeric]

Ryoko: let's say the total water volume of your system is 10 gallons...let's say that every day you have to replace a 1/2 gallon due to evaporation and the plant "drinking" it...in 10 days you will have added 5 gallons or 50%, in 15 days 75%, in 20 days 100%.

TD: then if you don't know the actual amount being given there are standards such as changing the water every 10-14 days regardless of how much they use.

user "Bigtoke" is an excellent resource for this kind of info also...since Lucas doesn't seem to be around lately.

 

[aeric]

...found Lucas posting away better than ever at the new C-W

 

[Guest]

Thanks aeric, I get it now.

 

[bostrom155]

tag

 

[ethereal]

excellent info, thank you lucas!

 

[sproutco]

Excellent thread.