Nutrient Binding

[bs0]

I've been told by several sources that you have to mix your nutes in a separate jug of water in order to avoid getting your nutrients bound to eachother. I can't think of why the concentration of the nutrients (in a cup vs in a water filled jug vs in the res) would have anything to do with a chemical reaction. Does anyone have any facts or chemistry to back this up? I'm convinced that the separate bottles are just a clever way to get more money from me, but I'm not sure. Anyone have some info?

Appreciated

 

[BurmeseDragon]

They won't bind but the water can only hold so many solubles in solution, so you can get some precipitation if you put to much in. It's always a good idea to see what settles out, letting the jug sit for awhile or you can pour in more than what was reading on the EC/TDS.

 

[*mistress*]

depends on the nutrients...
calcium nitrate often mixed separately... due to precipitation.
iron heavy metal mixed separately, ususally more avialble @ lower phs.

mg & k all different... assimilate @ different ph's & may fall out of solution @ certain phs...

in imaginary garden, feed cal separate than other nutes. not mobile & more available @ higher ph, generally.

this may be helpful.
Making your own Nutrients
https://www.icmag.com/ic/showthread.php?t=145251

enjoy your garden!

 

[Haps]

For me, it is better to mix my nutes in a bucket of water, I pour it back and forth between two buckets, blessing the water as I do it. I used to just add the nutes to my nute res, but I have much less if any precipitates this way.

 

[bs0]

depends on the nutrients...
calcium nitrate often mixed separately... due to precipitation.
iron heavy metal mixed separately, ususally more avialble @ lower phs.

mg & k all different... assimilate @ different ph's & may fall out of solution @ certain phs...

in imaginary garden, feed cal separate than other nutes. not mobile & more available @ higher ph, generally.

this may be helpful.
Making your own Nutrients
https://www.icmag.com/ic/showthread.php?t=145251

enjoy your garden!

Thanks for the reply and the direction.

 

[Darkstarlive]

completely unneccessary.
As long as you stir/agitate your water/res after each addition of base nutes and supplements you'll be fine.

Peace..

 

[*mistress*]

precipitation & ph...

precipitation & ph...

completely unneccessary.
As long as you stir/agitate your water/res after each addition of base nutes and supplements you'll be fine.

Peace..

precipitation occurs whether gardener recognizes or not...
ph main factor in keeping elements avaialble to plant & not converting into insoluble matter, that totlally useless to plant....

this is chemistry, as nutrients' are simply elements/compounds governed by laws of chemical equilibrium...

In hydroponic plant nutritional research, nutrient solutions can be considered as aqueous solutions of inorganic ions. In this aqueous solution, the ions are submitted to the laws of aquatic inorganic chemistry. This means that the ions are involved in the dynamic equilibria between complexation, dissociation, and precipitation reactions. These chemical reactions seriously impact elemental speciation and bioavailability. As a result, plant roots experience a different nutritional composition. Ions withdrawn from the-nutrient solution due to precipitation reactions, change the nutritional composition and are not available for uptake by plant roots. Like complexes, precipitates can buffer a nutrient solution, exchanging nutrients as these decrease by plant uptake....
the precipitation reactions that occur in hydroponic nutrient solutions. In the concentration range of nutrient solutions, no precipitates are formed involving potassium (K+), nitrate (NO3-), ammonium (NH4+), or sulphate (SO42-), while calcium (Ca2+) and magnesium (Mg2+) form mainly at a higher pH precipitates with hydrogen phosphate (HPO42-). Preparing nutrient solutions with tap water, calcium carbonate (CaCO3) is likely to precipitate. A good knowledge of the chemical reactions occurring in nutrient solutions is the first prerequisite in hydroponic plant nutritional research.

If the pH is maintained at 6.6 to 6.8, only about half the calcium in the water can be considered available to the plants.

The nutrient solution in a recycled system such as NFT... is so highly aerated that unless the pH is adjusted daily to about 5.8 to 6.0, calcium precipitates out of solution as insoluble calcium carbonate (limestone) and the pH rises. As a result, calcium deficiency is exhibited on the as dark brown to black specks like black pepper on the edges of the new leaves. When this occurs, the breakdown of the tissue is an excellent location of the Botrytis fungus to infect the lettuce. Similarly, NFT tomatoes can become calcium deficient as exhibited by blossom-end-rot on the fruit.

The preventive measures of calcium phosphate precipitation in nutrient solution for hydroponic cultivation were discussed as follows. The formation period, the pH an ion strength which precipitate calcium phosphates (CaHPO_4 2H_2O : brushite ; CaHPO_4 : monetite ; Ca_8H_2(PO_4)_6 5H_2O : OCP) in the ...standard solution which is typical composition in ...were examined. The nutrient solutions were prepared pH 6.4, 6.6, 6.8, 7.0, 7.2 and 7.4 by addition of KOH and ion strength values from 0.023 to 0.045 by addition of KNO_3. The results were summarized as follows.

1) The precipitation of calcium phosphate and more than 80% of appended Mn was complete in the period of 24 hours after the set up of the condition of nutrient solution in which pH was 7.4 and ion strength was 0.040.
2) The precipitation of calcium phosphate was dependent upon pH, p(HPO_4^<2->) and p(Ca^<2+>) of nutrient solution and was found above the condition of nutrient solutions in which pH was 6.6, p(HPO_4^<2->) was 3.91 and p(Ca^<2+>) was 2.70.
3) From the discussion on the calculations of thermodynamic condition of solubility equilibrium of calcium phosphate in... standard solution, brushite, monetite, and OCP precipitated above pH 6.8, 6.6, 6.4, respectively.
4) The preventive measure of calcium phosphate precipitation in nutrient solution for hydroponic cultivation were considered that the pH of nutrient solution was maintained under pH 6.4.

Extremes in pH can result in precipitation of certain nutrients.

For plant roots to be able to absorb nutrients, the nutrients must be dissolved in solution. The process of precipitation (the reverse of dissolving) results in the formation of solids in the nutrient solution, making nutrients unavailable to plants. Not all precipitation settles to the bottom of the tanks, some precipitates occur as very fine suspension invisible to the naked eye.

Plants can tell us their problems through leaf symptoms (e.g. Iron deficiency) when it's too late. Iron is one essential plant nutrient whose solubility is affected by pH which is why it is added in a chelated form (or daily). Iron deficiency symptoms occur readily. At pH values over 7, less than 50% of the Iron is available to plants. At pH 8.0, no Fe is left in solution due to iron hydroxide precipitation (Fe(OH)3 - which eventually converts to rust). As long as the pH is kept below 6.5, over 90% of the Iron is available to plants.

Varying pH of summer lettuce nutrient solutions also affects the solubility of calcium (Ca) and phosphorus (P). Due to calcium phosphate precipitation (Ca3(PO4)2) the availability of calcium and phosphorus decreases at pH values above 6.0. All other nutrients stay in solution and do not precipitate over a wide pH range. Poor water quality could exacerbate any precipitation reactions that may occur.

Generally in the pH range 4.0 to 6.0, all nutrients are available to plants. Precipitation reduces Iron, Calcium and Phosphorus availability at pH 6.0 and over .

The composition of 431 nutrient solutions for hydroponic cultivation of tomato, strawberry, ... hornwort and welsh onion were investigated from the standpoint of forming of calcium phosphate precipitation. The results were summarized as follows.
1) There were 23 nutrient solutions which had precipitation. These nutrient solutions had a higher value of electric conductivity, concentration of P, Ca, Mg, Fe and B than the other nutrient solutions which had not precipitation.
2) The composition of the precipitations in nutrient solutions were identified as brushite(CaHPO_4 2H_2O, dicalcium phosphate dihydrate) by using X-ray diffraction.
3) From the results if calculations of p(HPO_4^<2->) and p(Ca^<2+>) in nutrient solutions for hydropinic cultivation which were used by farmers, 16% of 431 nutrient solutions were supersaturated with equilibrium condition of brushite, but none of them were undersaturation with gypsum.

&

Why are some nutrients split into an “A” and “B” formulas?

Nutrients are split into two formulations because the phosphorus, calcium and sulfur nutrients need to be separated from each other. If this is not done, then the calcium and phosphorus, as well as the calcium and sulfur, in high concentrations, will react with each other to form calcium phosphate (cement) and calcium sulfate (gypsum). Both calcium phosphate and calcium sulfate precipitate out of solution, forming a white precipitate (which will usually fall to the bottom of the reservoir), and are unavailable to the plants. This will cause phosphorus, calcium and sulfur deficiencies in the plant. Once these nutrients are mixed together in the reservoir they are at lower concentrations and also a pH balanced nutrient mix will prevent the three nutrients from reacting with each other. This is another reason why balancing pH is extremely important.

Some nutrients are one part such as FloraNova Grow and Bloom, are extremely thick and need to be shaken well before mixing into the reservoir. If these nutrients aren’t shaken well before use then the precipitates that have formed at the bottom of the bottle aren’t remixed into solution. This will cause deficiencies, slow growth and reduced yields.

Some nutrients also come in three parts. This is done with some brands of hobby hydroponic nutrient formulas so that the grower can mix the three parts in different ratios to create different solutions for the vegetative and bloom stages, as well as for different types of plants, without having to switch to a different product. Most commercial formulas, however, are two part (you’ll never see a commercial hydroponic farm using a one or three part nutrient formula; they are primarily for hobby growers).

hope this helps. enjoy your garden!

 

[delta9nxs]

mistress, excellent post! saved.

 

[bs0]

Mistress-
If the nutrients are mixed directly prior to placing in the res, and the res is PH balanced to the 5.6-5.8 range will the precipitates re-dissolve? It seems like from your quotes that the important part is keeping the PH in the correct range?

Thanks a lot for your help on this, it's been wrecking my brain for the past couple days and my googling attempts were quite unsuccessful or just said 'don't do it' without any basis.

 

[Carl Carlson]

Mistress-
If the nutrients are mixed directly prior to placing in the res, and the res is PH balanced to the 5.6-5.8 range will the precipitates re-dissolve? It seems like from your quotes that the important part is keeping the PH in the correct range?

Thanks a lot for your help on this, it's been wrecking my brain for the past couple days and my googling attempts were quite unsuccessful or just said 'don't do it' without any basis.

Changing, if need be, the pH of the irrigation water so that it's in the correct range, is what enhances the chemical solubility of the nutrients in the water (hydroponics) or the soilless solution.

 

[vprising909]

well it seems to me that you shouldn't directly mix nitrogen and magnesium. I'm just going to sit back and listen on this one...

(and hey I've been told if you're using silica then you have to mix it separate...

the silica will bind to the nutrients.)

 

[*mistress*]

Mistress-
If the nutrients are mixed directly prior to placing in the res, and the res is PH balanced to the 5.6-5.8 range will the precipitates re-dissolve? It seems like from your quotes that the important part is keeping the PH in the correct range?

if the solution is ph-balanced in the 5.6-5.8 range, there shouldnt be precipitation. there should be dissolved salts, held in solution, & available to plants.

enjoy your garden!