Arcanepotato

I enjoyed this meme

It was not low effort to understand, but I got there comrade

No there isn't

I appreciate this joke.

Cs get degrees!

(I got 4 Ds in my academic career and I was grateful for each one lol 🥲)

Not exactly. Gases, particularly CO2, can dissolve in it, and form carbonic acid for example. That's why it doesn't have a pH of 7, but 5-6ish.

Fair - most of my distillation experience is not on water so I goofed in this fact (oversimplified)

AFAIK the TDS is the TDS700 to be precise, which is for measuring nitrogen or something. It's a really shitty and inaccurate unit, which is why the EC is the preferred measurement for many hydro growers, including me.

I think I'm missing some jargon.

TDS700? This is the method I am familiar with for TDS: https://edgeanalytical.com/wp-content/uploads/Waste_SM2540.pdf

Measuring nitrogen is a massive fucking pain with gross reagents but I suspect the nitrogen I work with is a lot different than nutrient mixes in hydro lol. Anything that needs a digestion step gets shipped to a Real lab.

I guess using conductivity for nitrogen is more about assuming the nutrient is "pure" but in different concentrations so you are just trying to see how dilute or concentrated it is based on the conductivity. I suppose that means it's it's a surrogate measurement not a direct measurement, which is why EC would be better than an actual TDS for that.

What you're saying is that the dissolved/ dispersed things aren't detectable by condictivity, did I understand that correctly?

If so, then there have to be visible particles. I will do further experiments and boil some off to see if there are residues forming.

Yes, but specifically that there are dissolved things that are not detectable by conductivity. No conductivity doesn't mean the solids must be non-dissolved. Not all things dissolve by breaking into ions. And not all ions give the same conductivity.

I misunderstood what you use the conductivity for - if it's to tell the strength of a known composition of unknown dilution, that's a pretty straight forward correlation.

Take for example the use of EC for TDS in drinking water, as described here: https://health.canada.ca/publications/healthy-living-vie-saine/water-dissolved-solids-matieres-dissoutes-eau/alt/water-dissolved-solids-matieres-dissoutes-eau-eng.pdf

The method most commonly used for the analysis of TDS in water supplies is the measurement of specific conductivity with a conductivity probe that detects the presence of ions in water. Conductivity measurements are converted to TDS values by a factor that varies with the type of water.(18,19)

Comrade, it is not distilled water and neither is your RO.

Distilling separates fractions in the liquid by boiling point. That's why it's not just boiling a pot of water and catching all the steam. You need to have some sort of idea of what you are separating and ensure you are collecting the distillate at the correct temperature (based on the atmospheric pressure). RO is - in an extremely simplified description - a filter, where particles that are small/soluble enough will pass through the membrane if sufficient pressure is applied.

Distilled water will have zero conductivity, RO will have some.

As an aside because I am insufferable: your meter says TDS but it's measuring conductivity. They are often used interchangeably because TDS is a massive pain to test at home. If you are always measuring the same thing, it's fine to use conductivity as a surrogate, but you can't compare the conductivity of sugar water to salt water and assume you have a good idea of the TDS.

I won't venture to comment about its use on plants but to folks asking about drinking it in the comments, please don't. Even if it was distilled it's hanging out in an environment full of airborne life and wouldn't remain sterile for long.

(Credentials? I got a D in mass transfer 20 years ago but I still somehow manage to work as an engineer and do a lot of lab work too. But nothing I've said isn't readily verifiable)

ITT people who don't understand irony

Yes, I find them beneficial. I prefer when the warning itself is spoilered too. That way I can choose to totally swerve the content and don't face anxiety over the subject matter at all.

I'm hot n ready (to smoke weed)

It's cold :(

H could also be "hierarchy is based sometimes, actually!"