YOUR TDS METER CAN'T DETECT THIS?

I am new to growing so please bare w/ me for a moment as I get to my questions.

My res behavior has become very predictable. I measure my ppms using the HM TDS-3. I see a slight drop in my ppms overnight, rise in my ph and drop in water level. Last night I deviated slightly from usual top off and this a.m. no drop in ppms, per usual. Everything else was per usual and look good.

This res top off had same ppms as usual, but this time included very small amounts of FloraNectar (1 ml/gal) and DM Silica (3 ml/ 5 gal). I went to HM website and found this statement:

As conductivity meters in disguise, TDS meters will only detect mobile charged ions. They will
not detect any neutral (uncharged) compounds. Such compounds include sugar, alcohol, many
organics (including many pesticides and their residues), and unionized forms of silica, ammonia, and
carbon dioxide.

I then went to Hanna website to see if this was true as to all ppm meters generally. They did not provide answer.

That was the extent of my due diligence (or lack thereof) prior to this post.

I have the following questions:

1. FloraNectar contains Cane Sugar, Malt Extract, and Molasses all of which seem to constitute ions undetectable by my meter. It does raise ppms when added to the nute solution. The DM Silica contains Potassium Silicate and other things and does not raise the ppms.

Does it make sense that the plant uptake of these products would slow or prevent the immediate uptake of other nutes accounting for the non-drop of ppms?

2. Are all ppm, tds, ec meters incapable of detecting the exclusions stated by HM?

3. If yes to #2, then are there instruments available to the typical ("cheap") grower to measure these inputs?

Thank you for your patience and time.

1. Floranectar contains K, Mg, and S as well as the sugars. These ions will affect the conductivity of the solution. Also, the silica isn't raising the EC because you are using so little of it( a 1:6300 dilution). Try a 1:100 or 1:200 dilution and see what happens.
2. Yes, any meter that measures electrical conductivity will not account for neutral compounds
3. Not that I know of.

in my experience BB is correct re: K2SiO3 not significantly raising the EC of your solution because the dilution rate is so great. when using K2SiO3 to raise pH i definitely found that EC will rise. at rates of 1:100 or 1:200 both the EC and the pH will shoot up.

ElusiveQuark said:

I am new to growing so please bare w/ me for a moment as I get to my questions.

My res behavior has become very predictable. I measure my ppms using the HM TDS-3. I see a slight drop in my ppms overnight, rise in my ph and drop in water level. Last night I deviated slightly from usual top off and this a.m. no drop in ppms, per usual. Everything else was per usual and look good.

This res top off had same ppms as usual, but this time included very small amounts of FloraNectar (1 ml/gal) and DM Silica (3 ml/ 5 gal). I went to HM website and found this statement:

As conductivity meters in disguise, TDS meters will only detect mobile charged ions. They will
not detect any neutral (uncharged) compounds. Such compounds include sugar, alcohol, many
organics (including many pesticides and their residues), and unionized forms of silica, ammonia, and
carbon dioxide.

I then went to Hanna website to see if this was true as to all ppm meters generally. They did not provide answer.

Click to expand...

But I can, via some scientifically minded and employed acquaintances of mine. I ended up learning this in a more roundabout way, but the conclusion is the same. EC, and therefore TDS and ppm measurements, can only occur with conductive molecules. Not all molecules are conductive, especially organic molecules.

ElusiveQuark said:

That was the extent of my due diligence (or lack thereof) prior to this post.

I have the following questions:

1. FloraNectar contains Cane Sugar, Malt Extract, and Molasses all of which seem to constitute ions undetectable by my meter. It does raise ppms when added to the nute solution. The DM Silica contains Potassium Silicate and other things and does not raise the ppms.

Does it make sense that the plant uptake of these products would slow or prevent the immediate uptake of other nutes accounting for the non-drop of ppms?

Click to expand...

I'm not sure I understand what you're asking. But my question to you is this; if it can't be (reliably/accurately) measured, then what are you measuring?

ElusiveQuark said:

2. Are all ppm, tds, ec meters incapable of detecting the exclusions stated by HM?

Click to expand...

Yes.

ElusiveQuark said:

3. If yes to #2, then are there instruments available to the typical ("cheap") grower to measure these inputs?

Thank you for your patience and time.

Click to expand...

Short answer is no. When I queried my scientist friends the basic issue is this--with specific regard to organic molecules, in order to measure them you need to first know what it is you wish to measure. THEN, you must purchase the lab equipment, which is rather specialized (i.e. you need a different piece of equipment to measure each type of molecule, EG seaweed extract, teas). None of this equipment is anything resembling inexpensive, let alone cheap.

I personally have tried using things like hydrometers to measure saturation of sugar in a solution, unfortunately, the hydrometer I have available is used for brewing and so requires a much higher percentage of sugar in saturation in order to make any meaningful measurement. A refractometer might be helpful here, but all you'll be able to measure will be specific gravity of salts or sugars, I know of no other molecules or compounds a refractometer may be able to measure accurately.

BasementBreeder said:

1. Floranectar contains K, Mg, and S as well as the sugars. These ions will affect the conductivity of the solution. Also, the silica isn't raising the EC because you are using so little of it( a 1:6300 dilution). Try a 1:100 or 1:200 dilution and see what happens.
2. Yes, any meter that measures electrical conductivity will not account for neutral compounds
3. Not that I know of.

Click to expand...

BB is right about everything except s/he's (and plastochron's) wrong about the silicon (not silica). When silicate salts get mixed with water they form monosilicic acid (a.k.a. orthosilicic acid), which is not ionized at normal pH, so your EC meter will not measure silicon content. it will however measure the partnering cations (K or Na) conductivity. as pH increases to 8.5 only 10% of your silicon can be ionized, when it gets to ~9.5pH you still only have ~50% ionization but no more than that. silicon content should be estimated with use of a nutrient calculator.

Also note that EC is relative to pH since pH is basically a ratio of acidic and alkali ions that have a huge effect on EC. so an accurate EC meter will have different results at different pHs.

Thank you all for your responses. You answered all of my questions. I have one more though (maybe two). Do you have a recommendation for the application (when and how much) of a silicon product? Is it a worthy supplement for most strains? Also, any recommendations for Cal-Mag during flower?

Thank you in advance.

Dizzlekush-

Also note that EC is relative to pH since pH is basically a ratio of acidic and alkali ions that have a huge effect on EC. so an accurate EC meter will have different results at different pHs.

Can you point me to a meter that considers ph in giving EC? Thanks!

y'all might want to read up on osmolarity, aka osmotic concentration. This is what the plants are most concerned with.

There's actually a fairly simple (not fast and not super accurate, though) method to determine TDS, it's called drying and is in fact closer to reality than conductivity measurements . Although, it's not very practical to boil down a litre or two of an aqueous liquid, trying to scratch of the few hundred milligrams of salts sticking to the bottom of your vessel, and then weigh these. Nonetheless, this is done for example in routine water quality testing (just take a lightweight vessel and weigh it before adding the liquid and then after drying, no scratching needed). Generally, standard EC measurements are simply used as convenient and fast approximation to estimate TDS in common water sources such as river water or diluted fertilisers.

Only Ornamental said:

There's actually a fairly simple (not fast and not super accurate, though) method to determine TDS, it's called drying and is in fact closer to reality than conductivity measurements . Although, it's not very practical to boil down a litre or two of an aqueous liquid, trying to scratch of the few hundred milligrams of salts sticking to the bottom of your vessel, and then weigh these. Nonetheless, this is done for example in routine water quality testing (just take a lightweight vessel and weigh it before adding the liquid and then after drying, no scratching needed). Generally, standard EC measurements are simply used as convenient and fast approximation to estimate TDS in common water sources such as river water or diluted fertilisers.

Click to expand...

can't you weight the vessel before you boil down the liquid and measure the vessel there after to get the weight of dissolved solids?

Precisely. Maybe I didn't point it out visible enough in the second last phrase, the part in brackets.

As a side note: TDS stands for total dissolved solids, EC only approximates total dissolved salts. AFAIK there is no alternative neat way other than to dry the water sample even if there's no organic matter in the water. This is under others because silica and boron don't affect EC (silicic and boric acid are mainly present in the non-dissociated form at normal neutral to acidic values) and carbonate/bicarbonate is highly pH and ion sensitive and can bias conductivity.

Fuck no your meter isn't going to tell you how much bullshit is in your bud or medium. The manufacturer doesn't disclose everything so don't forget to figure in that mystery. Elemental content isn't a Brix reading.
These bullshit plastic weed grow kits put sugar in fucking everything because it slows down the absorption of the plastic nutes (anyone who says bottled lab chemicals are equal to organic sources is a god damned bafoon). Thats how you get so fucking many plastic chemicals in your now plastic plants with out burning the shit out of em. Clog your roots with sugar uptake and start a new batch of problems way worse than the first (a natural yield from untrained plants, oh how horrible, you lazy asses)

I wonder what nutrients God used to get so high? Probably AN? Fuck all that shit and fuck that style of growing seriously. If you need fucking meters to grow plants,maybe you should let mother nature teach you a thing or two..