Getting to the bottom of the Phosphorus question in flower

im4satori

Well-Known Member
the way I would explain it as I see it is like this

lets say a common set of numbers for veg is

132 N
29 P
154 K

which is equal to 5 grams per gallon maxigrow





then take a bloom formula at roughly the same EC

66 N
86 P
154 K

which is 5 grams per gallon maxi bloom



now lets take a 50/50 mix of the maxigrow and maxi bloom at 2.5 grams each for a sum total of 5 grams combined

99 N
58 P
K 154
 

im4satori

Well-Known Member
those bloom mixes are notoriously known for containing way too much P and not enough N...ask arouund

your welcome to run the maxibloom formula starting out in early bloom but I would bet money your plants will yellow out from N def prematurely

maxi bloom has a ratio for very late bloom when your intentionally restricting N

as you begin looking at nutrient brands youll notice a common theme is to reduce the N each week thru bloom until finished

using the maxibloom alone your starting with a late bloom mix

if I used the brand

I would use the maxi grow during veg

the 50/50 mix during the first 6 weeks of bloom

and then the maxi bloom alone in late flower or I might just run the 50/50 mix to finish (which is what do)
 
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im4satori

Well-Known Member
ive also been mixing my own nutes for a decade and done a lot of experimenting

lucas

1:1:2

75:75:150


my mix

2:1:3

100:50:150




so my mix (at equal EC) has less P and more N with the same K

having said that its not really my mix its just the ratio I choose... I didn't make it up I got it out of a book based on science in hydroponics
 

im4satori

Well-Known Member
heres a common formula for mixing the GH 3 part per gallon

veg
9 mls grow
6mls micro
3mls bloom
2mls calmag

137 N
28 p
158 k

Bloom

3mls grow
6mls micro
9mls bloom
2mls calmag
1ml kool bloom

106N
67 P
154 K


then as you get to the later bloom they recommend raising the kool bloom which will push your ratio further toward the lucas mix in ratio pumping up the p&K

some people also mix the bloom like this

0mls grow
8mls micro
16mls bloom

106 N
92 P
158 K
 

ANC

Well-Known Member
Stop sweating the small stuff, let the microbes and fungi do the work like the good lord intended.
 
Maxi Series Recirculating schedule, mid bloom

I weighed out 1.5 tsp which is what's in the schedule and got 10.5g along with the full schedule is 182-201-420
If using 6g Maxibloom and the full schedule NPK is 123-123-282

Very high either way.

I'll be running Maxigro/bloom with some Si topping out at around 900 ppm on the meter.
Also Lucas using Holland Secret and some Si topping out at around 900.

I made a calculator in excel

A column = product name
B column = N%
C column = P2O5%
D column = K2O%

E column: Product in grams or ml
F column: =SUM(264.17*(B2/100))*E2
G column: =SUM((264.17*(C2*0.4364/100)*E2))
H column: =SUM((264.17*(D2*0.8301/100)*E2))

If adding multiple rows of product

=SUM(F2:F9) and so on.

Additional columns could be added for other minerals using the F column formula.

You can create multiple profiles on a single page and change weight values on the fly.
 

im4satori

Well-Known Member
im not sure why youd want to add silica with that much K already in your mix

I prefer to foliar feed silica cuz it doubles as a PM protector when foliar fed
if you don't adjust the ph down it can be as effective as green cure at the right dose

another thing
I don't know what your medium is but that's a pretty hot mix of fertilizer, you might find a lower EC more suitable with less potential for problems related to lock out

as for the npk ratio... youll learn it for yourself and realize what ratios work best
 
im not sure why youd want to add silica with that much K already in your mix
I'll be using a Maxigro/bloom mix like you suggested and doing similar with the Lucas. Silica supposedly has various benefits including root protection so I want to run it in the culture. I can do with/without and see what the effect is.

Running DWC, never had any problems with 900 ppm, but I will do a side by side with 750 and see what the difference is.
 

im4satori

Well-Known Member
ppm readings from a meter are hard to verify since it depends on the brand of meter you purchase....they have different conversion rates

my ppm meter might read 700ppm and yours could read 500ppm in the same solution if they are two different brands using different conversion rates

so I cant speak to ppm from the meter

EC is universal and the same no matter which brand meter you purchase and therefore technically more accurate for discussion

im thinking you know this already but I will say it just to make sure... the ppm readings given by your meter have nothing to do with the active elemental ppm we where discussing in fertilizer ratios

ppm readings from a meter aren't actual PPM
its just a conversion of EC and used as reference

why they confuse it by doing this I have no idea


another thing
your going to find that different mediums can handle different degrees of EC

a soil grow or maybe a coco or tupor grow can handle high EC above 1.5

where as a DWC or aero system or a Drain to waste system, all have the lowest EC requirements

most people who have success in these growing styles run there EC around 1.2 to 1.3 (never over 1.5)
 

im4satori

Well-Known Member
as a rule (but not in every case)

the frequency in which the root zone is exposed to the fertilizer solution irrigation/feeds the lower the EC requirements will be

soil grows might get watered every 3 days

coco might get watered 1x per day

dtw might get watered 6 to 12 times per day

DWC gets watered 24/7 and aero in most case does also

think of it like this

you can eat 2 huge meals per day or you can eat 6 smalls meals per day

at the end of the day you've consumed the same amount of calories but eating the small meals is more efficient for your body to process
 

im4satori

Well-Known Member
when you use the silica

use it 1x per week or two as a foliar spray up until week 3 of 12/12

DO NOT ph adjust the solution before spraying

you can use it at whatever ppm you wish but if you want to use it as a preventative for pests

do the math on your silica product..based on the amount of Si% figure out how much is required to achieve 200ppm Si and that's your max dose

I usually stick with around 175ppm because 200 seems to be a bit hot

anyway

mix your silica at 170 to 200 ppm Si and also add up to 1oz neem or azamax

again DO NOT ADJUST THE PH

the silica will push the ph waaaay up... that's ok that's what you want for this purpose

read up on green cure..it works by spraying the plants with a solution of high ph water mixed with soap
the high ph will mess up mold or mildew on the plants suface and the neem or even better azamax will act in the same way as the soap ...plus it also kills bugs

a far better choice than green cure with its broad spectrum of benefits

silica in the reservoir is nothing but a pain in the ass.. ph will do weird shit

if your source water has a real low ph fine it might help with that ..but most people already have to lower the ph daily..
all the ph down adds phosphorus with each addition
 

im4satori

Well-Known Member
what I would suggest is
keep a daily log of our EC and ph and reservoir changes and what you mix
manage your reservoir with these rules in mind;

EC/PPM goes down PH goes up = raise EC
EC/PPM goes up PH goes down or stays the same = lower EC

EC/ppm stays the same and ph rises slow = perfection

let your plants tell you how much they want, don't try and force feed them
 
Here's another NPK question. Is it correct to assume when articles are talking about fertilizer NPK ratios that they are talking about the guaranteed analysis or ppm ratio? For instance, I'm reading that mother plants are best grown with elevated P and lower N.

" Cuttings taken from the new growth of overly-vegetative plants tend to be weaker and more susceptible to wilting and fungal infection. Try using ½ strength nutrient formulas whenever possible, preferably with about 1:1 potassium to nitrogen ratio."

So in this case is the article suggesting a 1:1 ratio of N to P or a 1:1 ratio of N to P2O5?

I'm guessing what it's suggesting is something like 10-10-10 guaranteed analysis at half strength?

Source
http://npk-industries.com/resources_CARING_FOR_YOUR_MOTHER_PLANTS.html
 

im4satori

Well-Known Member
if theyre suggesting a ratio of N to K 1:1

then that would suggest your mix is equal in PPM

for example
120 N
60 P
120 K

that would be considered high P during veg and a 1:1 ratio N;K

with marginally low N (dwc you might be able to drop as low as 100ppm before showing N def in veg)

when I get up over 130ppm N the foliage and stems starts to soften and clones take slightly longer to root and are more prone to mildew
 
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LOL, I had P on my mind. Knowing that phosphorus plays a part in root growth I was wondering if increased P in a mother plant would be helpful. I found the article and didn't catch that higher K was what was being suggested.

Okay, so 2-1-2 fert would be close to 1:1 N/K ppm and 100 PPM N (I'm growing mom in peat/coir btw).
 

im4satori

Well-Known Member
LOL, I had P on my mind. Knowing that phosphorus plays a part in root growth I was wondering if increased P in a mother plant would be helpful. I found the article and didn't catch that higher K was what was being suggested.

Okay, so 2-1-2 fert would be close to 1:1 N/K ppm and 100 PPM N (I'm growing mom in peat/coir btw).
youll need to find the EC/ppm that works for you

ive not grown in peat so I cant say for certain but the peat might prefer a much higher EC/ppm than the plants in DWC
so 100ppm N in peat is likely not enough

what you could do is feed the moms your bloom mix and just supplement N as needed with something...im not sure youll need to ask but I wonder if you could add fish emulsion to get your extra N on stand by for the moms as needed

like I said ive not grown in straight peat but I think maybe you can use fish in it
 

im4satori

Well-Known Member
I would drop an extra pump in the bloom reservoir with a valve on it and use it to water the moms and either top dress with some calcium nitrate or water in some fish now and again

question;

are you adding lime and cooking the peat to get the ph buffered?
 
No I just use it from the bag. It's Promix HPCC, peat with chunk coir. It has PH buffers and mycorrhizae in it I think. Using Cocos A and B with CalMag. N-P2O5-K2O is 7-3-10 and ppm is 100-21-132. It's actually done a pretty good job, I was just wondering if there's anything I could do to make it better.
 

im4satori

Well-Known Member
No I just use it from the bag. It's Promix HPCC, peat with chunk coir. It has PH buffers and mycorrhizae in it I think. Using Cocos A and B with CalMag. N-P2O5-K2O is 7-3-10 and ppm is 100-21-132. It's actually done a pretty good job, I was just wondering if there's anything I could do to make it better.
I like those numbers for veg

especially for moms 100ppm does me about right,, I will veg at 120 to 130ppm but the moms do better with a modest amount of N

good call on your part

if your ph adjusting your water your likely getting enough P but 21ppm is a bit low

1mls ph down per gallon is roughly 11ppm P

Id personally like to see it around 35 to 40ppm but in veg you don't need much that's just my preference

what about some hydrolyzed fish... its 1-4-0 biweekly

or a wee bit of guano (high P) 1x per month ..maybe 1 tbs or something small
 
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