Bare with me, here as I explain why 1.7 as the target EC.
An EC of 1.7 is for comparison purposes on the buffering capacity since the other trials were run at 1.7. This EC, which is relatively high, was chosen as weāll be able to see the buffering regions ābetterā as the solution will have an elevated capacity.
One wouldnāt want to run a grow specifically at the ECs presented here. Youād rather use an EC that is sensible. We are simply determining how well a buffer works in relation to other buffers. Or, in this specific case, determining if there is some significant difference in the inherent buffering across several base nutrient formulations.
If the buffering capacity at an EC of 1.7 were to appear better than MC (with a similar EC), it would remain better if we were to lower the ECs for both of them and re-ran the measurements. As long as any buffers in a formula is homogeneous, the buffering capacity decreases along with decreasing EC and; likewise, different formulas will be relative to each other.
We can see this effect in the plots previously presented when adding buffers. The curves at various concentrations appear the same but they show less capacity when we reduce the concentration. The same thing should occur with the base nutrients since we are treating them as though they were a buffers (titration).
A buffer with poor capacity can actually be perfectly acceptable if there is little unbalanced H+/OH- exchange occurring. Buffers handle any unbalance in the biological exchange. The greater the unbalance, the more buffer capacity may be needed.
Without knowing the rate of H+ / OH- exchange that actual occurs, the plots actually tells us nothing about time. It does tell us that higher concentrations of buffering components can buffer more H+ / OH-. It also tells how much ābetterā one buffer is compared to another.
For instance, if you were to build a buffer solution, you could use much less MES relative to a citrate buffer. Or, for that matter, much more of a phosphate buffer to achieve the same effect. But, we could only guess how much would be useful for any particular situation since we donāt know anything about the unbalanced exchange (fwiw, this can theoretically be calculated but letās not because itās hard and has hundreds of possible variables).
For comparing two base formulations, what weāll get thatāll be useful is simply that one has more (or less) buffering capacity or differing regions than the other. Along with previous experiments and the hands-on experience, weāll possibly glean some additional hints on how PH behaves at a basic solution level thatāll be useful in the future and, perhaps, help untangle some of the current theories.
This may sound confusing or argumentative but was not the intent. Just trying to explain the line of thinking. Which is sort-of stream of consciousness, squirrel!
