Come on you could of used ur degree to make that bit more informative and explanatory, no?
It doesn't need to be, and my degree tells me also not to over-explain where simplicity and brevity will do the trick. That doesn't happen often, and so we should revel in it when it does.
However, to oblige you a bit--it has to do with, as I said, the instantaneous needs of the plants. These are constantly changing, as are the concentrations of various compounds. Lower concentration might turn a protein on that makes more--or it might trigger a protein to control gene expression so that instructions will be made to create new proteins to make more of it--or any number of possibilities.
The idea is that it is a moving, breathing, changing thing--there is no "perfect" value. It's also worth noting that for each 1pH unit change--the hydrogen ion concentration changes ten-fold. Its nice to have a pretty number from 1-14, but you must think at the scale of the reaction.
5.3 and 5.4 pH are DRASTICALLY different values on the molecular scale--its not a tiny thing.
Also in a more general sense, this all has to do with entropy--I'll leave you to you own investigations on that note.
And really that answer doesn't apply to the UC specifically or indoor gardening generally, wouldn't you say?
Sure it does, on both accounts. Biochemistry is the same everywhere (generally speaking).
This is just what science can tell you from the beginning, before you explore anything else. Experience can tell you a whole bunch of other cool stuff--but it's not going to make as much sense as it can if you don't start with all the available information.
The information available is that there is no perfect pH value, even if there is an optimal one (and there likely isn't, but rather a collection of "local" optimal values occurring at different times based on the needs of the plant).
Now, maybe a certain pH gives you the best results every time--but its important not to look at that data with foggy glasses on, that try to convince you that must be "the perfect" value--it's just what worked for you in a non-experimental setting if we're being honest.
Instead, it would be better to take more exhaustive data points of all physical values (temp/pressure/humidity) and attempt to correlate these (along with pH values) to success/failure of given plants.
That will get you closer to a "perfect" value--but ultimately the answer is that the perfect value only comes at the perfect time and place, it's not static.
