Mixing micros for consistency of analysis

[Pepere]

I am currently using GLA EDTA & DTPA micromix.

Recently I was advised that due to the ground of the mix and it being designed for commercial use, mixing it in 500 ml solution batches can yield significantly variable batches with ratios between elements varying from the guaranteed analysis on the container by a significant margin.

It was suggested to mix larger batches to minimize this issue..

The question is, How big a batch?

Would mixing up a gallon of solution be sufficient?

 

[Burr740]

The bigger the batch the more likely it is to have the intended ratio (because you're using more dry product at once)

A 500 ML solution is better than dry dosing 1/8 tsp. A gallon is better than 500 ML

Honeslty I wouldnt sweat much over solutions of 500 ML and up. The main thing is to not dole it out in tiny fractions of a tsp

 

[BenB]

You can literally see the different layers of powders in my CSM+B. It's not like looking at the strata in rocks in geology class, but it's obvious it isn't thoroughly mixed. So I get your frustration. I wanted to mix my own, but I was in a bit of a pinch and just ordered some micros from this dude that sells them.... maybe on here. I haven't used them yet because something different came in first. (I over ordered several things in a moment of panic and indecision), but I'll be firing them up soon.

 

[Burr740]

I wanted to mix my own, but I was in a bit of a pinch and just ordered some micros from this dude that sells them.... maybe on here.

Haha, thanks Ben! I hope you like them

I havent seen GLA's '+DTPA' product in person. I suspect they just blended dtpa Fe in with csm-b (which is all their other micro mix is) Put both in something like a concrete mixer and stir it up. Mechanically mixing two things in relatively similar amounts does create a fairly homogeneous blend. Their claimed ratio between csm-b and dtpa is likely correct

Its the csmb that is in question when it comes to dosing our aquariums. Its made using some type of agglomerating/granulation process to wind up with the tiny pellets that ideally containing everything in the right ratio. (a lot of things are made like that, can look it up to learn more)

This process works best when the compounds are in relatively equal amounts to begin with, by weight. Like macro ferts containing N, P and K. But with micros, the amounts of each compound are not even remotely close, especially when Fe is added to the mix

About half the dry weight of csm-b is the edta Fe (224 grams in 1 lb) The next highest thing by weight is B, about 22 grams in 1 lb of csmb. The smallest thing is Mo, about 750 milligrams in 1 lb.

To manufature one ton of csmb requires mixing 1000 lbs of Fe, with 97 lbs of B, and 3.5 lbs of Mo. There is zero chance that each little granule of csmb contains the right amount of everything. But its not supposed to, thats not the claim

The guaranteed analysis isnt derived by analyzing a single piece or two, or even a tablespoon. By law the minimum amount used to determine the guaranteed analysis is usually 1 lb (varies a little between ferts)

So its more of an average. If you dissolve a pound of csmb in water its going to have the right numbers of everything. Even a tablespoon should be close. But when you get down to small fractions of a tsp like we use, the chances of having everything in the right amount become very slim

Thats why its best to use as much as you can at one time