A thread on nutrient recipes, and some reference links
Posted 06 June 2006 - 02:21 AM
Growing Greenhouse tomatoes
"The cation exchange capacity of the soil
When small quantities of inorganic salts, such as the soluble mineral
matter of soil and commercial fertilizers, are added to water they dissociate
into electrically charged units called ions. The positively charged ions
(cations) such as hydrogen (H+l, potassium (K+l, calcium (Ca2+l,
magnesium (Mg2+), ammonium (NH:), iron (Fez+), manganese (Mn2+1,
and zinc (Zn2+1 are absorbed mostly on the negatively charged surfaces of
the soil colloids (microscopic clay and humus particles) and exist only in
small quantities in the soil solution. Thus, the humus-clay colloids serve as
a storehouse for certain essential ions (cations). The negatively charged
ions (anions), such as nitrates (NO; 1, phosphates (HPO:?, sulfates WI-I,
and chlorides (Cl-), are found almost exclusively in the soil solution and can
therefore be leached away easily with overwatering. The roots and root
hairs are in intimate contact with the soil colloidal surfaces, which are
bathed in the soil solution, and therefore nutrient uptake can take place
either from the soil solution or directly from the colloidal surfaces (cation
As plants absorb nutrients (ions) they exchange them for other ions.
For example, for the uptake of one potassium (K+) ion or one ammonium
(NH:) ion, one hydrogen (H+) ion is released into the soil solution or
directly into the soil colloids by the process of cation exchange. Similarly,
for the uptake of one calcium (Ca2+) or one magnesium (Mg2+) ion, two
hydrogen (H+) ions are released by the root. Thus, as the plant absorbs
these essential cations, the soil solution and the colloidal particles contain
more and more hydrogen (H+) ions, which explains why the removal of
cations (ammonium (NH ‘;I nitrogen is a good example) by crops tends to
make soils acidic, i.e., having a low pH. Also, as the plant absorbs essential
anions such as nitrates (NO ;1 and phosphates (HP0 4 ), the soil solution is
enriched with more and more hydroxyl groups (OH-1 and bicarbonates
(HCO; 1, which explains why the removal ofanions (nitrate (NO; 1 nitrogen
is a good example1 by crops tends to make soils alkaline, i.e., having a high
The above article seems to suggest that K and Mg are stored in medium, whereas N and P are not. Maybe this leads to nutrient mixes like Canna Coco that are very low in K, and Mg, maybe because they accumulate in medium? But Canna Coco, and also Pure Blend Pro, are also very low in P, which the above article says leaches out rapidly. so I dont understand why those nutes are so low in P... maybe it has to do with their being designed for tap water, expecting the addition of pH down (Phosphoric acid), which adds P?
I was also looking for info on which nutrients are mobile within the plant, versus which ones are only stored in the medium and uptaken as needed (non mobile nutrients). I did not find that info yet, but invite others to point it out if you read the Greenhouse Tomato article.
Now for some heavy math based discussion of some popular nutrients
the following specs are in N-P-K-Mg format
canna aqua a plus b vega 6-3-8-1
Canna aqua a plus b flores 4-4-11-1.2
Canna Coco a plus b flores 5-5-3-1
Flora Nova Bloom 4-8-7-2
Flora Nova Grow 7-4-10-1.5
Flora Micro 5-0-1
Flora Bloom 0-5-4-1.5
from the above data, using pH's spreadsheet, http://www.angelfire...premixppm3b.zip
with weights checked, the following dosages produced the net elemental values for the following GH, Canna, and PBP formulas.. I strongly encourage folks to input the net weight of their nutrient bottles when using pH's premix spreadsheet. Thick products like FloraNova, especially benefit from this data, because it raises the net NPKMG calculations significantly.
note the Canna Coco Bloom recipe profile, it is about a 33% dilution of the 8ml GH Micro, plus 16 ml per gallon of GH Bloom formula.. (but with more Nitrogen).. Maybe medium based nutes are intentionally weak, so they accumulate in the pot?
8ml GH Micro 16 ml GH Bloom, is my guru pH's baseline bloom formula (pH is a person) derived from the Mel Frank targets, which suggest a 100-100-200-60 goal for NPKMG values in bloom Both GH Flora series nutes and the Flora Nova series, achieve Mel Franks targets without additives. Here is a link to Mel's specs http://www.angelfire...es/profiles.htm
pH's "Lucas Formula" values for 8ml micro, 16ml bloom
8 Flora Nova grow. Flora Nova is the one bottle solution to nutrients, note this mix is almost identical to Canna Aqua Vega, and GrowGreen's Nute Recipe
GH's baseline Flora Series, the 3 bottles, green purple and red, (different from Flora Nova series) veg formula
GH 15grow, 10micro, 5bloom
and GH 3 part bloom formula
GH 5grow, 10micro, 15bloom
canna coco 5.7a plus 5.7b (this is their baseline 3ml per liter formula), the highest dosage they recommend is 14ml/gal of canna coco A plus 14 of B). This mix (5.7ml/gal) is less than 1/3 strength of GH Flora Nova Bloom @8ml per gallon on the P, K and Mg..
canna coco 8/a and 8/b
Here is canna coco's strongest bloom mix, before the pk14 boost. it resembles the GH FloraNovaGrow recipe in its Nitrogen level
canna coco 14/a and 14/b
Here we see Canna Coco hitting hard with P and K
canna coco 14/a and 14/b plus 6ml pk13-14
pk 13-14 alone
here is Canna Aqua Vega at mfg rec of 3ml per litre each of A and B (very similar to GH's veg mix)
and here is Canna Aqua Flores at 3ml/litre each of A and B (it does not resemble GH bloom recipes, but is slightly similar to 15ml PBPBloom plus 5ml Cal Mag)
Here is PureBlendPro Bloom @ 15ml/gal
and PBPBloom 15, plus 5 cal mag (GrowGreen's formula) it resembles the grow formula of FloraNova @8ml, as well as GH's 15Grow, 10Micro, 5 bloom formulations, the most copied recipe Ive found. It seems competition only copied GH's veg formula for the most part..
Note also that GrowGreen has contributed a total nutes per crop spec, of 15ml per 40 gallons, or 20 ounces of PBPBloom per 1k crop.. a very interesting spec, resulting in about 5000 total ppm of N per croplife..
I dont know why Canna and PBP use such lower P and Mg levels than GH, nor do Canna and PBP hit Mel Franks 100-100-200-60 targets the way GH does. Yet folks with Canna and PBP produce excellent results, just like folks with GH do.
There does seem to be a difference in the design of Canna Aqua compared to Canna Coco, and PBP is similar to Canna Coco.. which leads me to think that DWC nute levels can be much higher than medium based nutes that expect accumulation to occur in the medium..
Bear in mind that when looking at Canna Aqua Flores, the K level is rather high, and this inhibits uptake of Mg, which is already a bit low imho.. I have heard repeatedly that Canna Aqua, AND Canna Coco produce Mg deficiency if not supplemented with Epsom at the rate of 1/4tsp per gallon...
I used to recommend PBP be supplemented with Epsom also, but Cal Mag is a better option, as it also adds N
I hope this thread helps to develop an archive of effective nutrient mixes. I can add analysis of other products and combinations if people want to know their profiles and are not spreadsheet savvy.
To do that, I need guaranteed analysis info from the label of the products being used, as well as the net weight of the bottled products.
for those not familiar with the origin of the "Lucas Formula", it was developed by pH in his Ebb/Flow system. I adopted his recipe for DWC, after learning about bubblers from Highgrade. I assumed that DWC and Ebb Flow could be fed at the same nutrient strength and ratios. It worked. I dont know why Canna and Botanicare (makers of Pure Blend) use such lower P and Mg levels.. Even if they are designed for medium, does not Ebb Flow have similar nute accumulations as medium based grows? Maybe not. Even though Ebb Flow does concentrate nutes in the rox between irrigations, they may be flushed out each time the flood comes, unlike the case with Canna Coco, or PBP in soilless mixes like Sunshine..
But to confound that possibility, here comes GrowGreen in ebb flow, using PBP, and its low P and Mg levels..
Its still a mystery to me why GrowGreen gets such good results from such low nute concentrations, whereas folks like ceteris paribus, also in ebb flow, get similar good results as GG, but using the Lucas Formula, with its higher P and Mg levels..
At this stage of my learning, out of all the possible systems and nutrients, Im inclined to recommend Ebb Flow with Flora Nova nutrients. I remain loyal to GH because of the simplicity of using no additives, and now also because the Nova series has everything in just one bottle.
The one reason to consider PBP in my opinion, is that folks think of it as "organic". To understand more of the details comprising the use of the term organic, check out this article on the GH website:
"Many attempts have been made to create the perfect organic-
hydroponic nutrient, but so far nothing matches the purified
mineral salts used in formulating hydroponic nutrient solutions.
We note that the European Economic Community (EEC) has
established the category of "mineral organic" for foods grown with
the required mineral nutrients to supplement an organic base of
nitrogen. We previously touched on the fact that United States
agricultural regulations are currently set and applied at the state
level but practically all states prohibit the use of refined ingredients
to cultivate “organic" crops; only mined minerals can be used.
Surprisingly, this precludes organic growers from using
pharmaceutical or food grade ingredients to formulate fertilizers."
I hope others will help me learn more about the reasons why non GH nutes are so low in P and Mg..
GH has LESS potassium than canna or PB
> Here is a quote from MyNamisStich def thread with regards to high K levels and why the K proportion in the PBPro and Canna are lower than most.
The K levels in PBP and Canna are actually higher than in GH
The recipe with the lowest K and highest Mg is from GH, not Canna nor PB
The recipe with the most P in it is also GH, not canna nor PB
> When you have "too much" Potassium in your soil
how much is "too much"?
I believe K levels become a problem above 400ppm, none of the recipes show that level
notice stich is talking about soil, where nutes accumulate more and more over time
In hydro, nute levels should NOT be accumulating higher and higher over time as they can in soil or coco.
The highest K level is in the Canna Coco and Canna Aqua, over 300ppm, GH and PB stay close to 200ppm
Canna is notorious for needing epsom salt to add Mg. Pure blend was the same way, until they came out with Cal mag and sweet, both of which are Mg boosters.
Lets focus on the K (Potassium) and Mg levels in GH, Canna, and PBP
GH FloraNovaBloom 180ppm of K, plus 62ppm of Mg
Canna Coco with the PK 13-14 boost they recommend; 317ppm of K, 42ppm of Mg
Canna Aqua Flores 316ppm of K, 42ppm of Mg
PBPBloom with Cal mag 214ppm of K, 45ppm of Mg
in EVERY case, there is LESS potassium in GH than in Canna or PB
afaict, Canna and PB work DESPITE having MORE Potassium, and less Mg than GH
Canna uses 3 products, A, B, plus epsom
PB uses 2 products
GH Flora uses 2 products
GH Flora Nova uses only 1 product
how many products would you like to be using to supply your plant nutrition needs?:-)
Posted 06 June 2006 - 02:28 AM
lucas formula is tried and true.
anyone unsure should just follow his advice,
then once u grasp things yerself, u can modify to suit your/your plants needs accordingly.
glad it helps.
Posted 06 June 2006 - 08:28 PM
too much math.
yet another good reason to
thx for posting it, cap.
i'm sure some hydro-hed somewhere can use the info.