Can anyone explain PPM or TDS?

Hey everyone, im new here and had a few questions.

I have been doing a lot of research on hydroponics and still dont have an understanding of ppm or tds.
My question is if anyone can explain in. What effects do nuetrients play. I am thinking of trying the Lucas Formula with slight alterations but do not know how that will affect the ppm/tds.

If you can give an example like 3ml/gal floragrow increases ppm by____? Idk if that makes sense, but if it does to anyone I would love to hear about it. Thank you all

ppm = parts per million. So if you have 400 ppm you have 400 parts of X for every million parts of water. There is no simple conversion as each fertilizer contains different stuff (X).

TDS = total dissolved solids. This is also a measurement of how much of X there is in a solution.

EC should also be added. EC = electro conductivity and is a measure of the salt content of a solution. Chemical fertilizers are salts and salinity levels change the way electricity flows through water. By measuring electro conductivity you can measure salt content which is correlated to fertilizer amounts. Most cheap test pens measure EC and use that measurement to calculate a guess at ppm/TDS.

Just buy test pen, follow the recommended dosage schedule, and don't worry about the rest. All fertilizers increase TDS, ppm, and EC.

What roles do nutrients play? Nutrients are what plants are made of. Plants are made of carbon from the air and nutrients from the ground. Without nutrients your plant dies.

Basicaly ppm,ec,and tds are all a measure of ppm. PPM is the strength of the mutes you are feeding your plants. At given stages of growth a plant can only take up a certain strength of nute. Get a TDS meter if you don't have one already, mix your nutes as suggested then check the ppm adjust as needed. here's a scale that I use and have good success. you can vary it if you think the plant can take more or less..hope this helps.

seedlings, early sprouts.....100 to 250
early veg.........................300 to 400
full veg............................450 to 700
early bloom......................750 to 950
full mature bloom..............1000 to 1600

Thank you gastanker and deetee for such quick and informative responses. You knowledge is greatly appreciated.

Another question...
What do you think the optimal ppm/tds, and ec levels should be through each specific stage of life? The more opinions the better. Thanks

Use the scale I just sent you, or did you post this before I did. Bare in mind ec is a scale that some meters use instead of ppm, most meters use ppm, and that's you main concern.

Yes, the Info. above is good. A decent book on the subject will explain...maybe a
youtube vid out there as well. Stay within the range so the plants uptake all that
they can, outside the ranges tree's have trouble with in-taking nutrients. One more
thing, start out with the cleanest or know what the values are of the water you are
using.....minicipal tap water is crap (at least in my area it is 540 ppm) dirty water will
add salt's to the mix

Thanks for the input. I was thinking of going to my local fish store and buying reverse osmosis water because its ph nuetral... Would that work out? Thinking about it, it may be salty due to the fact it would be from a fish store... What would you suggest? Distilled water from the grocery store?

If it's for a couple trees lugging around RO (reverse osmosis) water is
ok, distilled water is ok to, but will be more $. One thing about filtered/
distilled water...it works too good. Usually you will have to add calcium-
magnesium - iron (CalMag or SensiCal Mg Mix) to your feeding program
the trees will indicate what it's lacking when using super clean filtered
water.