Salt/Chemical Fert Mixing Examples
Rather than just giving you a cookie cutter recipe, that likely wouldn't relate to your specifically available salts, I thought it would be better to just illustrate the thought process that goes into creating your own mix..
Okay, so let's say we just sprouted and we want to introduce our first feeding. If you remember from my earlier PPM segment (Go to the Temple for training if necessary), you want
N150, P100, K120, Ca75, Mg75, S25, Fe15, Cl15.
We'll mix by the liter. I start with nitrogen as the base nute. I want 150PPM using a 5-1-1 fish emulsion. If you remember the PPM conversions, 3 grams would give us a supply of micronutes as
150PPM of N
30PPM of P
30PPM of K.
We need more P,K as well as Ca, Mg, Ca. If you premixed some of the concentrated SupertriplePhosphate solution (4800PPMs) I recommended (again, back to the Temple...its under the "TDS, EC, PPM" section), one TB of this would provide an additional.
72 PPM of P
21 PPM of Ca
2 PPM of S.
If you add up the numbers, you can see we have just about targeted the N and P levels. We need to up the K. I'll use Muriate of Potash 0-0-60 and 45 Cl...which is an often neglected micronute. This is highly water soluble, so I mix this in the liter of distilled water. I let it sit for a couple days while occasionally shaking. This allows most of the excess chlorine to evaporate into the air. (I am just going through the thought process...when actually mixing, I mix this FIRST and let sit for a while to evaporate excess Cl) We need about 70-90PPM so 1/8 gram would yield
75 PPM of K
56 PPM of Cl
Our total available nutes so far?
N 150PPM
P 102PPM
K 105PPM
Ca 21
Mg 0
S 2
Fe 0
Cl 56 (or less if you allowed to evaporate)
We need Ca, Mg S.
I would add 1/10 gram of Hydrated Lime which would supply 50PPM of Ca. Set there.
Magnesium Sulphate (Epsom salts) is cheap and easy to find. 1/5 gram would provide 22 PPM Mg and 28PPM of S.
This mix could use another 50PPM of Mg, but this was just a freestyle example. Keep in mind, tap water usually has between 200-400PPM including Mg, Ca, Cl, Cu.....
Iron is also a bit short by the looks of things. I add about 1/2gram of Iron Sulphate which adds the following nutes in PPMs.
Fe 16
Cu 1
Mn 2
Zn 2
There are also micros in the fish emulsion.
This mix would more than suffice. The one flaw would be the shortage of Mg. This is often a problem because many popular Mg sources have overly high concentrations of S.
If you wanted to REALLY exact the balance, there are 2 solutions. You could use Dolomite Lime instead of Hydrated lime. That way you could have Mg supplied with your Ca and you supplement Sulphur separately via Epsom salts or with Iron Sulphate....You could also use Magnesium Oxide....a raw salt, or Magnesium Nitrate...but these are a bit tougher for most to find.
I should mention that there IS a preferred order of mixing.
Generally, you want to introduce the salts in order of their macros, secondary, micro relationship....N then P then K, Ca, Mg, S, Fe./..and so on...
My N source is not a salt, but emulsion and my P source is the premixed solution I made.
The Muriate of Potash is my main salt and highly soluble, so I actually add that in first. People often ask me about the high levels of Cl from tap water, potash, emulsion, etc, sooo.....
To reiterate from an earlier post.... "Chlorine evaporates quickly first of all. Also, when Chlorine is added to water, it forms hypochlorous acid and hydrochloric acid. Hypochlorous acid DOES kill living things by disabling cellular functions. BUT, when added to the growing medium, the hypochlorous acid combines with nitrogen to form chloramine. It IS therefore, necessary to have Nitrogen in your soil if adding high levels of Chlorine."
I then add the epsom salts which supplement 2 main secondaries.
Then dissolve the Hydrated or Dolomite lime...the Ca ions will be suspended as H ions are replacing those that were removed through formation of HCl. Depending on what grade it is, this stuff may seem to just float on the water at first. It takes a while, but it will eventually settle and dissolve.
I THEN go back and add in the fish emulsion, TSP solution and then liquid Iron for micronutes. |